db design or query

hi,
I am fairly newb to mysql, so excuse my silly question. I am working on a vbmysql application for a warehouse. Here I am importing an excel sheet to mysql which has weekly status of the products. I am storing it in the same table with date and product code and qty.
I want to display the weekly report and monthly report. Monthly report is easy but the problem is getting distinct values of rows as different columns for weekly report. i.e. I have stored dates, which I want to pick up distinct in different columns i.e.

qty where week(idate)=week(20080818)-4, qty where week(idate)=week(20080818)-3, ..... and so on.

I cant get it to work. I was wondering if there is a flaw in my db design, if so any suggestions how do I fix it? if not, then how do I get this query to work

thanks in advance,

regards,