Is there a way through VBA code to add a new table to an existing query? Also is it possible to update a Sum column to include a new table in the sum?

I have the following Sum Column. And each time a new table is added I would want that table to be reflected in the formula below. Is it possible to grab the below formula with vba code then add onto it then post it back to the column? Not sure how this would be done.

Total Points: [Weekof17July2011.TotalPoints]+[Weekof24July2011.TotalPoints]+[Weekof31July2011.TotalPoints]