Multiple condition SUMIF

Hi i have a list of product codes, and for each i need to sum a value column but in weekly chunks.

For example for week 1 i need to sum the value column for each individual product code for the dates 23/4/07-29/04/07 and then do the same for week 2 onwards. There are 17 product codes.

I attach the sheet in question, can anyone help please?

Thanks.

Not really, thanks for this though, but i need to do it using formulas into the template sheet?

Perhaps something like this?

Let me know

Regards

Dav

Exactly like that. Thanks both for your help. Much appreciated.