Spreadsheet With Many Rows Of Data

I have got a spreadsheet with many rows of data. One row is product name and the other is date written. Now I want to calculate how long these entries have been on the log. So lets say I have 10 entries called Pension all with different dates and 10 entries called ISA with different dates. So first I need it to look for all the proucts called "Pension" and then to work out how many are 0-3 weeks old and so on. So i want it to look like this but a formula to work it out for me and to update it automatically.

0-3 Weeks 4-6 Weeks 7-9 Weeks 10 Weeks +
Pension 4 3 3 1
ISA 3 4 1 2

(this does not display very well here but I hope you understand what I mean)

I am using Excel 2003 and I dont think it as a WEEKS function so I will do it in days and then devide by 7.

I know that to look for the product i use
=COUNTIF(H:H,"Pension")

The H:H is because the product is on colum H on my spreadsheet

I know to find the date it is
=TODAY()
So to work out something 3 weeks old it would be

=TODAY()-21