IF/THEN string in multiple sheets excel

hello,
I'm trying to figure out how to do the following:

I have two sheets in one excel document.
SalesRep_42 (one sheet) is where I will be projecting data from RawData (another sheet)

RawData has all the raw data that i exported from our accounting software.

If a cell in column A in the RawData sheet contains the number 42 (sales person's ID number), I would like to add total sales together from row AA (Gross Sales) and have that number displayed in a cell on the SalesRep_42 sheet.

Does that make sense?

This would get me started at least.

Next, I would like to do the same thing except, add another variable in the formula so that i can pull numbers from each month.