Data Validation w/ Sum in Excel

Hello All,

I just found out about the drop down menu (Data Validation) feature, but I have a question in regard to it.

I am trying to create a list of totals that will have a possible 8 categories to fit into, determined by the drop down menu. I would then like to have 8 separate subtotals that give me the sum of all the totals that fit into category 'A', category 'B', and so on. The original totals will be added to one of the eight subtotals, which one to be determined by the category selected in it's drop down menu.

The only solutions I can think of seem excessively long winded. Does anyone have any ideas or suggestions?

Thank you!