Modifying fields not available in User exit

 

*Step 1: Assign the program/field name of calling program variable to field symbol 1
assign '(zcall_program_name)fname_from_call_program' to <fs1>.


*Step 2: Assign field Symbol contents to field symbol  2
assign (<fs1>) to <fs2>.          


*Step 3: Assign Field Symbol 2 to avariable in the current function module/Program
vbap-vbeln = <fs2>.