I have a spreadsheet where I update the col index number each week to reflect
the new weeks data for about 100 customers. At this point each week I go in
and change the col_index_number in each vlookup by 1 (100 times). Is there
an easier way?

Problem 2;, I also change the graph range to reflect the prev most 6 weeks,
thus these charts (100) need updated each week as well. Can anyone help?