Total Summary of Multiple Worksheets

Hi

I am trying to create a Summary Totals page of payments made to employees over a 12 month period (April 09 to March 10), i.e. one worksheet per month. There are starters and leavers each month so each worksheet has new rows added and some taken off. The summary sheet must me a long list of all employees that have ever appeard on any of the sheets, bearing in mind that some may come and go during the period. They all have a unique employee numbers. There are between 2500 and 3000 rows on each worksheet.

I attach a copy of the header row for the sheets.

Thanks

Regards

Cortlyn