BILLS: Include Balance Due on history bills.

I would like to suggest adding the balance due to a historical billing statement. If the bill is filed with the court the Judge will want to see the total due. I have been saving the bill as a text file, calculating the balance due by hand and typing it in. 1) this is an added step, 2) calculating by hand leaves room for error and 3) the text version is not visually appealing to look at and provide to the court or our clients.