Collecting From Multiple Sheets to One Spreadsheet

Hello Guys: Need Some help

I have a spreadsheet that I use every week, new spreadsheets are created each week when I have generated time sheet and invoice etc.

I want to be able to collect certain data from these spreadsheet in to one spreadsheet for accounting purposes, total VAT, Total expenses etc. so I can submit just one form of data to accountant per month or even per year.

At the moment I have in one folder about 20 spreadsheets relating to last 20 weeks and many more to come in the forthcoming weeks until the the end of financial year. so we have definite names of spreadsheet as well as wildcard names for those that are not in folder yet.

Can anyone help ?

Regards

ASH