Is there a way to make a parent category for To/From transfer categories?

I have a Line of Credit (LOC) that I use to cover cash flow issues. I'm constantly transfering from and to the LOC. I have incorporated the trasnfers (To LOC, From LOC) into the budget (both as expense groups so they show up together). As expected, when I borrow from the LOC, the $$ show up in the "From LOC" category, and when I "make a payment", the $$ shoq up in the "To LOC" category (so far, so good). What I really want to see, is the net result of the transfers back and forth (am I breaking even, reducing the amount owed, or going further into debt). In order to do this I have to manually do the math for each month to see how I did.

Is there any way that I can make these two categories sub-categories of a parent category so that the budget does the math?