I have 2 lists of information that I'm using to make one and I am trying to
create a lookup formula to connect the information.

Here is my formula:
=IF(ISNA(LOOKUP(A4,L$4:L$2340,P$4:P$2340)),"",LOOK UP(A4,L$4:L$2340,P$4:P$2340))


I have used it before and it seems to work but now I try and copy it and it
is not working.

The information in Column L and P are style numbers that are alpha numeric,
would that make a difference?