How to edit standard CFL in SAP 9.0?

Hi all,

I want to edit standard Choose From List in Itemcode Field in Marketing Documents in order to search only Itemcodes whose Property 1 is ticked.

Is there a way to edit standard Choose From List in SAP 9.0 in Itemcode's field in Marketing Documents matrix? Or is there a way to add choose from list in a UDF in SAP 9.0?

Thanks in advance,
Vasilis Korolis