Using a calculation to mimic a portal?

I have the following problem: The child table is records of line items with an AmountPaid field related to the original parent table by a numeric field, ApplicationNumber. I have six calculation fields in the parent that need to contain the AmountPaid values for the first six related records (one-to-one) from that child table for export (along with a ton of other data from other related tables) to a csv file for upload to a mainframe.

The user doesn't need to see/manipulate these values, so I don't need a portal in a layout. The original programmer created 6 different relationships with 6 fields in the parent table composed of ApplicationNumber & ".1", ApplicationNumber & ".2", etc. In the child table he had a field composed of ApplicationNumber & "." and a field which was a lookup on a Count calculation of related records back in the parent table, mimicking the behavior of Get(RecordNumber) in a Find operation to get the requisite match. It worked, but it hurts my brain everytime I see it. Is there a clearer, easier way to do this?

Thanks,

MichaelE