Suppress the single quote when display downloaded file in EXCEL

Question

I have a requirement to keep all the cells contents left-justisfied when display in EXCEL. I used GUI_DOWNLOAD and concatenate a single quotes to the numeric fields in my internal table. However, when open the file in EXCEL, the single quote show up in the cell also. Anyone knows how to suppress the single quote when open in EXCEL? Here are my codes:
concatenate '''' itab-field2 into itab-field2.
modify itab.
   CALL FUNCTION 'GUI_DOWNLOAD'
     EXPORTING
       filename                      = 'c:test_xls.xls'
       FILETYPE                      = 'ASC'
       WRITE_FIELD_SEPARATOR         = 'X'
     tables
       data_tab                      = itab.
Thank you,

Answer 1

Check the below program :
REPORT ZJOINS message-id z01. .
*REPORT ZTEST3 line-size 400.
DATA : V_CHAR(1) TYPE C VALUE ''''.
data : v_field(12) type c.
data : begin of itab occurs 0,
       fld1(12) type c,
       end of itab.
start-of-selection.
v_field = '0000012345'.
CONCATENATE V_CHAR  V_FIELD  INTO V_FIELD.
itab-fld1 = v_field.
append itab.
CALL FUNCTION 'WS_DOWNLOAD'
EXPORTING
  BIN_FILESIZE                  = ' '
  CODEPAGE                      = ' '
    FILENAME                      =
    'C:\Documents and Settings\smaramreddy\Desktop\fff.xls'
   FILETYPE                      = 'ASC'
  MODE                          = ' '
  WK1_N_FORMAT                  = ' '
  WK1_N_SIZE                    = ' '
  WK1_T_FORMAT                  = ' '
  WK1_T_SIZE                    = ' '
  COL_SELECT                    = ' '
  COL_SELECTMASK                = ' '
  NO_AUTH_CHECK                 = ' '
IMPORTING
  FILELENGTH                    =
  TABLES
    DATA_TAB                      = itab
  FIELDNAMES                    =
EXCEPTIONS
   FILE_OPEN_ERROR               = 1
   FILE_WRITE_ERROR              = 2
   INVALID_FILESIZE              = 3
   INVALID_TYPE                  = 4
   NO_BATCH                      = 5
   UNKNOWN_ERROR                 = 6
   INVALID_TABLE_WIDTH           = 7
   GUI_REFUSE_FILETRANSFER       = 8
   CUSTOMER_ERROR                = 9
   OTHERS                        = 10
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
I just tried one field in internal table,i am not sure this program help you
Thanks
Seshu