in the formula, how about you:
a) use shared/global variables so that they persist across the report
b) use a qualifer/flag so that they only load once.
I was thinking of OnFirstRecord, but you have 2 records it looks like.
So the next would be to have a record counter, which increments every row and you want <2... I think that there is a report variable about the row number, but since I haven't used, I don't remember what it's called. I am sure that you can find it in Help.
HTH