Using Excel 97. I have strings of text, which comprise a unique key in an
Excel spreadsheet. Each week a new spreadsheet is compiled along with this
unique key

I have the current - prior unique keys side by side in a separate sheet tab.
I tried using the EXACT text function to identify matching records, but my
formula only finds matches if next to one another.

How do I get it to find any matches in rows above or below? My current
formula looks something like:

=EXACT($A1, $B$1:$B$300)

My actual data in many cases is larger than 300 rows.

Thanks for any help/suggestions