You can dynamically assign a Search Help name to a field. Here is the code you need.
IF rad1 EQ 'X' . " Sales Order matchcode_object = 'VMVA' . ELSEIF rad2 EQ 'X' . " Delivery matchcode_object = 'VMVL' . ELSEIF rad3 EQ 'X' OR rad4 EQ 'X' . " Invoice matchcode_object = 'VMCF' . ENDIF . CALL FUNCTION 'HELP_VALUES_GET_WITH_MATCHCODE' EXPORTING * DISPLAY = ' ' * FIELDNAME = ' ' * INPUT_VALUE = ' ' matchcode_object = matchcode_object * TABNAME = ' ' IMPORTING select_value = docno EXCEPTIONS invalid_dictionary_field = 1 invalid_matchdcode_object = 2 no_selection = 3 OTHERS = 4 . IF sy-subrc <> 0. ENDIF.