BAQ: What is possible in a calculated field?

Is it possible to have a 'Find First' statement in a calculated field? If so, does anyone have an example. This is for a straggler's report. What I am trying to do is find the 'LAST' Previous.OpSeq < the current.OpSeq.

Once I have that record then I think I can calculate the AtLocationQty by getting the difference from the Previous Operation's QtyCompleted and Current Operation's QtyCompleted.

does anyone know if this is possible?