Balancing

So this one is pretty hard to explain, and I'll try my best... Searcher all over the internet and I couldn't find anything, not sure if I was searching the "correct terminology"

My wife and I are trying to set up Sub-Accounts within our Savings account using excel. The savings account will have X amount of dollars in it, and the excel sheet will have that X amount of dollars broken down into different Sub-categories (christmas, car repair, etc...) using a %. Each month we add X dollars, and those dollars get broken up, using a fixed % into each sub category.

I am sure I am already re-inventing the wheel, I just want to do this myself so I know its "right"

My problem is, how do I add a one-time adjustment into the sheet... that "disappears" once added in. I have it set-up so that if we take a withdrawal from the sub-account, that it will effect the total in that account... however, in my "Adjustment" category, the negative number still appears... I want the ability to add in the withdrawal (or one time deposit), have an effect on the total, and then disappear..

Can this be done??

Thanks,

~refi