You're welcome.
Hope this makes sense. It might help with grouping on the weeks - to split the data into sub-groups of a manageable size. So the 50 weeks could be grouped into, say, 5 higher-level groups: and then do the double-click trick on each of the five goups.
Excel's row limit is 65,536. You can take it from Excel to Access to overcome Excels' limit.
Sounds like you're there. Cheers, Fazza