Good afternoon,
I am using EXCEL 2007

I have 2 workbooks (see below) and would like to use a function to extract
and show only the suffix of a file name either pdf or xlsm from book 1 to
book 2. I have vlookup now but do not know how to get only the suffix of
the file name. Is there a way to get only the "pdf" or "xlsm" by using
vlookup? I am open to using any function if there is one better.

Thanks in advance.

Example

Book 1
123 123.xlsm
456 456.pdf

Book 2
456 pdf
123 .xlsm

Current Function:
=VLOOKUP(A1,[Book1]Sheet1!$A$1:$B$3,2,FALSE)