Macro Help needed

[wberry]

Hi all

I have a workbook with a sheet called Data_Set, this sheet has a list
of numbers on it. I then download from our finance system another list
of numbers into a new workbook called Info Tech Maint.xls.

I need a macro that will compare the numbers in each list & if there is
a number on 1 list that isn't on the other list it will write a error
to a sheet called "cost centre errors" on the first workbook.

The error it writes needs to tell me which list is missing the number

Thanks