Standard PO Form, changing supplier LOV

I would like to be able to change the supplier LOV to be able to filter by vendor number (segment1) as well (either filter by vendor name or their number). I noticed that in the POXPOEPO form, the LOV and SQL statement are in the form itself.

Would I be able to create a clone of the seeded form, and somehow let Apps use the new one, or will I have to use forms personalization?

Has anyone ran across this problem before? 

Thanks!