hi Richard,
As Nabheet mentioned, you can create a exit(function moudle) assign it to your search help.
blow code will help you:
*"----------------------------------------------------------------------
*"*"Local Interface:
*" TABLES
*" SHLP_TAB TYPE SHLP_DESCT
*" RECORD_TAB STRUCTURE SEAHLPRES
*" CHANGING
*" VALUE(SHLP) TYPE SHLP_DESCR
*" VALUE(CALLCONTROL) LIKE DDSHF4CTRL STRUCTURE DDSHF4CTRL
*"----------------------------------------------------------------------
FIELD-SYMBOLS: <fs1> type SHLP_DESCR,
<fs2> type DFIES.
IF callcontrol-step = 'SELONE'.
CALL FUNCTION 'DD_SHLP_GET_DIALOG_INFO'
CHANGING
shlp = shlp_tab.
* logical to change the label text.
read table shlp_tab ASSIGNING <fs1> index 1.
read table <fs1>-fielddescr ASSIGNING <fs2> with key fieldname = 'KUNNR'.
if sy-subrc eq 0.
<fs2>-scrtext_m = 'KUNNR'.
endif.
ENDIF.
regards,
Archer