Hi,

What I'm suggesting is use
=IF(ISERROR(INDEX(A1:AW13,MATCH(Y18,A1:A13,0),MATCH(Y19,A2:AW2,0))),"",INDEX(A1:AW13,MATCH(Y18,A1:A13,0),MATCH(Y19,A2:AW2,0)))&IF(ISERROR(INDEX(A1:AW13,MATCH(Y18,AB1:AB9,0),MATCH(Y19,A2:AW2,0))),"",INDEX(A1:AW13,MATCH(Y18,AB1:AB9,0),MATCH(Y19,A2:AW2,0)))

If you had Excel 2007 of course that could be much simplified.