automatically balancing Scheduled Transactions

[J.P. Lien]

I'm trying to set up a scheduled transaction for my mortgage payment.  I
used the druid, but had to make some changes to the template transaction
(I've paid extra on the loan in the past, so the ppmt function doesn't
return the right value).  When I was done I got the following warning:

"The Scheduled Transaction Editor cannot automatically balance this
transaction. Should it still be entered?"

I guess this is telling me that the editor can't verify that the
transaction will balance every time.  It should be balanced based on the
way I entered it, but I can see how it would be better to make certain.
 Is there some magic variable that I can put in to capture any imbalance?

Thanks,
J.P. Lien