Date shown with a different format in MS Excel spreadsheet

Question

Dear forumers,
I have quite an odd problem with my report program. In this report, I will need to send an attachment file (.XLS) in an email before displaying the report output in ALV. The FM, 'SO_DOCUMENT_SEND_API1' is used to send the email.
Everything works perfectly except for a strange date format issue (only happens in the attachment file).
Sample Output (see the last line):-
10/22/2009                                                                               
09/30/2009                                                                               
02/23/2009
04/22/2009                                                                               
07/28/2009
03-05-09
In my program logic, I manually format all the dates (via concatenation) from YYYYMMDD to MM/DD/YYYY. And in debug mode, I checked that the last line in the internal table (see above) is also written as "03/05/2009". What could have possibly gone wrong here (the rest of the displayed date formats are fine)?
Please do help. Thanks.
Codes:-
" Create local string variables
  DATA:
  lv_user         TYPE string,
  lv_lockdate     TYPE string,
  lv_new_lockdate TYPE string.
  LOOP AT i_usr02[] INTO w_usr02.
" Get user ID and locked date
    lv_user     = w_usr02-bname.
    lv_lockdate = w_usr02-pwdlockdate.
    IF w_usr02-pwdlockdate IS NOT INITIAL.
" Format locked date
      PERFORM format_date CHANGING lv_lockdate
                                   lv_new_lockdate.
" Insert user ID and formatted locked date
      PERFORM concatenate_append USING lv_user
                                       lv_new_lockdate
                                       c_tab.
    ELSE.
" Insert user ID only
      PERFORM concatenate_append USING lv_user
                                       space
                                       c_tab.
    ENDIF.
" Clear string variables
    CLEAR: lv_user,
           lv_lockdate,
           lv_new_lockdate.
  ENDLOOP.

Answer 1

Further codes (subroutines):-
DATA i_attach       TYPE STANDARD TABLE OF solisti1.
"&      Form  FORMAT_DATE
"       Subroutine to format date ( MM/DD/YYYY )
"      --> PV_DATE        Date ( YYYYMMDD )
"      <-- PV_NEWDATE     Date ( MM/DD/YYYY )
FORM format_date  CHANGING pv_date    TYPE string
                           pv_newdate TYPE string.
" Condense date string first
  CONDENSE pv_date.
" Concatenate portions of date string accordingly
  CONCATENATE pv_date+4(2) pv_date+6(2) pv_date+0(4)
    INTO pv_newdate
    SEPARATED BY c_slash.
ENDFORM.                    " FORMAT_DATE
"&      Form  CONCATENATE_APPEND
"       Subroutine to concatenate two strings and a new line
"       and finally appending it to the internal table
"      --> PV_STR_1     First string variable
"      --> PV_STR_2     Second string variable
"      --> PV_FLAG      Flag (TAB or SPC indicator)
FORM concatenate_append  USING    pv_str_1 TYPE string
                                  pv_str_2 TYPE string
                                  pv_flag  TYPE char3.
" Concatenate two string parameters
  IF pv_flag = c_space.
    CONCATENATE pv_str_1 pv_str_2
      INTO w_attach_tmp
      SEPARATED BY space.
  ELSEIF pv_flag = c_tab.
    CONCATENATE pv_str_1 pv_str_2
      INTO w_attach_tmp
      SEPARATED BY c_htab.
  ENDIF.
" Insert a carriage return + line feed as well
  CONCATENATE c_crlf w_attach_tmp INTO w_attach.
" Append workarea to table before clearing workareas
  APPEND w_attach TO i_attach.
  CLEAR: w_attach,
         w_attach_tmp.
ENDFORM.                    " CONCATENATE_APPEND