Export Screen to Flat Text file

Question

Hello,
I'm very new in SAP and need to modify a little program.
I would like to export the current screen in a flat text file.
The file must be stored on the SAP server ( /usr/sap/data/bel) so not on my local harddrive.
I searched and found found functions like WS_download and GUI_download, but I'm not sure how to use them. Can somebody help me please?
Curent Code of my report:
REPORT ZAT_CLRDEP01.
Tables declaration
tables : vbrp,bkpf,bseg.
Data declaration
data: begin of itab1 occurs 0,
          vbeln like vbrp-vbeln,
          arktx like vbrp-arktx,
          belnr like bkpf-belnr,
      end of itab1.
data: begin of itab2 occurs 0,
          vbeln like vbrp-vbeln,
          arktx like vbrp-arktx,
          belnr like bkpf-belnr,
      end of itab2.
data: begin of itab3 occurs 0,
          kunnr like bseg-kunnr,
          name1 like kna1-name1,
          vbeln like vbrp-vbeln,
          zfbdt like bseg-zfbdt,
          belnr like bkpf-belnr,
          augcp like bseg-augcp,
          augbl like bseg-augbl,
          arktx like vbrp-arktx,
      end of itab3.
data: begin of itab4 occurs 0,
          kunnr like bseg-kunnr,
          name1 like kna1-name1,
          vbeln like vbrp-vbeln,
          zfbdt like bseg-zfbdt,
          augcp like bseg-augcp,
          augbl like bseg-augbl,
          arktx like vbrp-arktx,
          pswbt like bseg-pswbt,
      end of itab4.
data: vbeln_tst like vbrp-vbeln.
Selections
parameters accgrp like vbrp-ktgrm default '03' obligatory.
parameters compcde like bkpf-bukrs default 'LOI' obligatory.
select-options: billdoc for vbrp-vbeln.
select-options: customer for bseg-kunnr.
select-options: fiscyear for bkpf-gjahr.
select-options: reldate for bseg-augcp.
select-options amount for bseg-pswbt.
INITIALIZATION.
  fiscyear-low = sy-datum(4).
  fiscyear-high = sy-datum(4).
  append fiscyear.
  reldate-high = sy-datum.
  append reldate.
  amount-low = '100'.
  amount-high = '2000'.
  append amount.
START-OF-SELECTION.
  refresh: itab1,itab2,itab3,itab4.
  clear  : itab1,itab2,itab3,itab4.
  clear: vbeln_tst.
  select * into corresponding fields of table itab1
    from vbrp inner join bkpf
    on    vbrpmandt = bkpfmandt
      and vbrpvbeln = bkpfxblnr
    where vbrp~ktgrm = accgrp
      and bkpf~bukrs = compcde
      and bkpf~gjahr = fiscyear.
  loop at itab1.
    if itab1-vbeln ne vbeln_tst.
      move itab1-belnr to itab2-belnr.
      move itab1-vbeln to itab2-vbeln.
      move itab1-arktx to itab2-arktx.
      append itab2.
    endif.
    vbeln_tst = itab1-vbeln.
  endloop.
  loop at itab2.
    select * from bseg
                  where bukrs = compcde
                    and belnr = itab2-belnr
                    and gjahr = fiscyear
                    and buzei = '001'
                    and augcp in reldate
                    and augbl ne ''
                    and vbeln in billdoc
                    and kunnr in customer.
      if sy-subrc = 0.
        move itab2-belnr to itab3-belnr.
        move bseg-kunnr to itab3-kunnr.
        select single name1 from kna1
                      into itab3-name1
             where kunnr = itab3-kunnr.
        move itab2-vbeln to itab3-vbeln.
        move bseg-zfbdt to itab3-zfbdt.
        move bseg-augcp to itab3-augcp.
        move bseg-augbl to itab3-augbl.
        move itab2-arktx to itab3-arktx.
        append itab3.
      endif.
    endselect.
  endloop.
  loop at itab3.
    select * from bseg
                where bukrs = compcde
                  and belnr = itab3-belnr
                  and gjahr = fiscyear
                  and hkont = '0000488600'
                  and pswbt in amount.
      if sy-subrc = 0.
        move itab3-kunnr to itab4-kunnr.
        move itab3-name1 to itab4-name1.
        move itab3-vbeln to itab4-vbeln.
        move itab3-zfbdt to itab4-zfbdt.
        move itab3-augcp to itab4-augcp.
        move itab3-augbl to itab4-augbl.
        move itab3-arktx to itab4-arktx.
        move bseg-pswbt to itab4-pswbt.
        append itab4.
      endif.
    endselect.
  endloop.
END-OF-SELECTION.
  sort itab4 by kunnr.
  loop at itab4.
    at first.
      write:/ '   customer                    ','billing doc.',
      'Billing date',' Release date','Release doc.',
     '            material                         ','G/L amount'.
    endat.
    write:/ itab4-name1.
    write at 36 itab4-vbeln.
    write at 47 itab4-zfbdt.
    write at 61 itab4-augcp.
    write at 74 itab4-augbl.
    write at 88 itab4-arktx.
    write at 127 itab4-pswbt.
  endloop.
Thanks in advance!
Kindly regards,
Nico

Answer 1

Hello,
Thanks for your help and fast reaction, I added the 'open dataset' but probably made some minor error:
I'm getting  field "result" (name of my text file) is unknown. It is neither in one of the specified tables or defined by a 'DATA' statement
Currently have following code:
Objet du programme :                                                 *
      Recherche de documents de facturation SD sur base de           *
      l' "account assignment group" de l'article                     *
      Stocker ces valeurs dans une table interne afin                *
      de retrouver les pièces comptables correspondantes.            *
      Afficher le N° du document de facturation, celui de la         *
      pièce comptable, la date de release du release document.       *
REPORT ZAT_CLRDEP01.
Tables declaration
tables : vbrp,bkpf,bseg.
Data declaration
data: begin of itab1 occurs 0,
          vbeln like vbrp-vbeln,
          arktx like vbrp-arktx,
          belnr like bkpf-belnr,
      end of itab1.
data: begin of itab2 occurs 0,
          vbeln like vbrp-vbeln,
          arktx like vbrp-arktx,
          belnr like bkpf-belnr,
      end of itab2.
data: begin of itab3 occurs 0,
          kunnr like bseg-kunnr,
          name1 like kna1-name1,
          vbeln like vbrp-vbeln,
          zfbdt like bseg-zfbdt,
          belnr like bkpf-belnr,
          augcp like bseg-augcp,
          augbl like bseg-augbl,
          arktx like vbrp-arktx,
      end of itab3.
data: begin of itab4 occurs 0,
          kunnr like bseg-kunnr,
          name1 like kna1-name1,
          vbeln like vbrp-vbeln,
          zfbdt like bseg-zfbdt,
          augcp like bseg-augcp,
          augbl like bseg-augbl,
          arktx like vbrp-arktx,
          pswbt like bseg-pswbt,
      end of itab4.
data: vbeln_tst like vbrp-vbeln.
Selections
parameters accgrp like vbrp-ktgrm default '03' obligatory.
parameters compcde like bkpf-bukrs default 'LOI' obligatory.
select-options: billdoc for vbrp-vbeln.
select-options: customer for bseg-kunnr.
select-options: fiscyear for bkpf-gjahr.
select-options: reldate for bseg-augcp.
select-options amount for bseg-pswbt.
INITIALIZATION.
  fiscyear-low = sy-datum(4).
  fiscyear-high = sy-datum(4).
  append fiscyear.
  reldate-high = sy-datum.
  append reldate.
  amount-low = '100'.
  amount-high = '2000'.
  append amount.
START-OF-SELECTION.
  refresh: itab1,itab2,itab3,itab4.
  clear  : itab1,itab2,itab3,itab4.
  clear: vbeln_tst.
  select * into corresponding fields of table itab1
    from vbrp inner join bkpf
    on    vbrp~mandt = bkpf~mandt
      and vbrp~vbeln = bkpf~xblnr
    where vbrp~ktgrm = accgrp
      and bkpf~bukrs = compcde
      and bkpf~gjahr = fiscyear.
  loop at itab1.
    if itab1-vbeln ne vbeln_tst.
      move itab1-belnr to itab2-belnr.
      move itab1-vbeln to itab2-vbeln.
      move itab1-arktx to itab2-arktx.
      append itab2.
    endif.
    vbeln_tst = itab1-vbeln.
  endloop.
  loop at itab2.
    select * from bseg
                  where bukrs = compcde
                    and belnr = itab2-belnr
                    and gjahr = fiscyear
                    and buzei = '001'
                    and augcp in reldate
                    and augbl ne ''
                    and vbeln in billdoc
                    and kunnr in customer.
      if sy-subrc = 0.
        move itab2-belnr to itab3-belnr.
        move bseg-kunnr to itab3-kunnr.
        select single name1 from kna1
                      into itab3-name1
             where kunnr = itab3-kunnr.
        move itab2-vbeln to itab3-vbeln.
        move bseg-zfbdt to itab3-zfbdt.
        move bseg-augcp to itab3-augcp.
        move bseg-augbl to itab3-augbl.
        move itab2-arktx to itab3-arktx.
        append itab3.
      endif.
    endselect.
  endloop.
  loop at itab3.
    select * from bseg
                where bukrs = compcde
                  and belnr = itab3-belnr
                  and gjahr = fiscyear
                  and hkont = '0000488600'
                  and pswbt in amount.
      if sy-subrc = 0.
        move itab3-kunnr to itab4-kunnr.
        move itab3-name1 to itab4-name1.
        move itab3-vbeln to itab4-vbeln.
        move itab3-zfbdt to itab4-zfbdt.
        move itab3-augcp to itab4-augcp.
        move itab3-augbl to itab4-augbl.
        move itab3-arktx to itab4-arktx.
        move bseg-pswbt to itab4-pswbt.
        append itab4.
      endif.
    endselect.
  endloop.
END-OF-SELECTION.
  sort itab4 by kunnr.
EXPORT OUTPUT TO FLAT TEXT FILE :                                    *
open dataset result for output in text mode.
if sy-subrc = 0.
loop at itab4.
at first.
write:/ ' customer ','billing doc.',
'Billing date',' Release date','Release doc.',
' material ','G/L amount'.
endat.
write:/ itab4-name1.
write at 36 itab4-vbeln.
write at 47 itab4-zfbdt.
write at 61 itab4-augcp.
write at 74 itab4-augbl.
write at 88 itab4-arktx.
write at 127 itab4-pswbt.
transfer itab4 to result.
endloop.
close dataset result.
endif.
Thank you!
Regards,
Nico