Within the form routine 'get_exit_titles' of z<rggbr000> (copied) program
add the below details at the endof of the routine.
exits-name = 'UXXX'. give the form name that you want to use in exit (XXX is any number that you want to use
( exits-param = c_exit_param_none. "If need to work on single line item
OR exits-param = c_exit_param_class. ) "if complete data used in exit.
exits-title = text-101. "Text that you want to use
than add a rountine 'UXXX' at end of the includle ( again UXXX is the routine name that you used in the above section while adding the routine name to the exits table. within this routine you can add your logic to return result which is a boolean value.