My Idea is for you to create the posibility for the user to be able, when he is creating a formula column, to create a DIFFERENT formula on each cell/row. Exactly like in EXCEL. this way we will be able to use and link multiple colums and results.
if its to difficult to do it, then create the posibility for the user to be able to CREATE a different formula for each GROUP. Basically this could be a possible workaround in many situations. This workaround can help many of us to deal with calculations.
If one of those option can be possible, this will make a lot of people happy.