I have a folder that contains about 1700 workbooks, each workbook containing one worksheet. There are 1-2 workbooks for each group and I need to merge those workbooks together. I have seen code that will merge every book in the folder, but I need to only merge ones for each group.

Ex.

aaa_book_1.xls
aaa_book_2.xls
aab_book_1.xls
aab_book_2.xls
aac_book_1.xls

should become

aaa_full_book.xls
aab_full_book.xls
aac_full_book.xls

Not all of the locations have both workbooks, but none of them have more than 2 workbooks.

Can anybody help me to automate this with either VBA or .Net?

Thanks,
Mike