Excel worksheet merge

I have been given the job of merging around 2,000 workbooks, each having around 12 worksheets. So I expect to have 24,000 worksheets in total. I am looking for a utility that will merge these onto one continuous worksheet, or if this is too big, I will initially group them into smaller worksheets. My problem is, I need to audit which workbook each row of data is taken from, so the utility must insert a column with the workbook name inserted against each row.

This is a nightmare, but I have to do it. Can anyone suggest any utility, at any price, that might carry out this function ?

Thanks in advance

 

A friend of mine goes here for help,try it
http://ozgrid.com/forum/index.php