Hi
You need to maintain OB74 configuration for the GL ABCD for your company code. Assign the parameters as assignment (ZUONR) and Amount (WRBTR). Now when you run F.13 the items will be cleared. This will clear all the items which have the same Assignment and debit/credit amount meet.
If however, you want to clear only a specific item(s) in F.13 you can also specifiy the document no in the initial selection screen or use F-03
regards
Sanil Bhandari