Sorry but I don't have an answer for you.
I am not sure if you were talking about native Exact forms or the Exact Forms Plus Add On from Juiced. But either way I don't have a great answer.
I don't think it can be done with the juiced add-on and while I'm not an expert on need of exact forms, I believe you can only use a table report configuration for the query there as well so I think that won't work either.
grasping at straws a bit it might be possible to push a button on see an order, I will assume that these are some kind of customer order documents, And put focus on the order. Then you would have summary fields that would summarize back up to the table where the stage is come from to put the summary totals up there and then the exact form would be generated off that summary table.
But I think they would take some one on one consulting to try to coax that to work.