See also my video link which should make things clearer.
It's less than 90 seconds.
I have 3 sheets;
Sheet1 - Detail for rest of workbook
Sheet2 - Summary of Sheet1
Sheet3 - This is my problem one! It should display a "drilldown" of the active SubCatID chosen in sheet2. (i.e. it will depend on where the customer places the cursor in sheet 2).