Hi Siong,
1. Z_FI_REP_000001 is name of custom program. You can use any script to call the subroutine in this custom program. (ZNSC_CHANGE_CORRESPONDENCE or Z140_CUS_STAT_02). The prequisite is you must write the statements to call the routines.
2. The variable ®UH-ZBUKR& and &L_TEXT& need not be found inside the print program. It should be present in script. In your case, remember you have three objects a) script b) print program (program RFKORD11) c) custom include. So data declared in Z_FI_REP_000001 need not be same as script or program RFKORD11.
Let me know if you still have open questions.
Thanks,
Sachin