Using multiple SELECT statements

I'm pretty new to this, so I could really use some help. Here's my problem: I need to create a report that sums a bunch of lines from my databse. The problem is, it all comes from different tables and uses a lot of different fields. There are about 25 different summaries I need to do. Is there a way to use a different record selection (SQL Select statement) for each of these 25 items?

What I have now, I can set my Record selection to work for one out of the 25, but because the others have different requirements, they do not return the correct values. What I want is to be able to make 25 seperate SQL queries for each of the 25 items. I hope this made sense, and thanks for any help you can give.