Instead of going into each file to post an EMD (personal check or cashier's check from client) why can't there be a deposit slip with 15 lines that can post up to 15 checks to 15 different files at one time.
Format would be:
File # tab to next cell source of funds tab to next cell enter the amount of deposit and have that information post directly to the corresponding file #. This is also done inside Quickbooks in the "receive Payment" area.