Hi, I have an excel worksheet (I will call it A.xls), its first column is
the unit numbers, I did some work with this file and saved it under a
different name (I will call it B.xls). I noticed some of the rows with unit
numbers are missing in this second file.

Could some one tell me how would I go about in comparing the first columns
of these two files so that it will give me a list of missing unit numbers
that I had in the file A.xls but now not present in B.xls

Thanks a lot in advance. - Kenny