What happens with an auto-charge when a credit exists on the customer account?

What happens with an auto-charge when a credit exists on the customer account?

If I have a customer with a recurring invoice that is set up to auto-charge, how do I make sure that the charge takes into account whether or not the customer has a credit balance?  If I have issued a credit to the account, I don't want to charge the customer for the invoice amount, but for the net amount of the newly created invoice and the credit.  Does the auto-charge take this into consideration?

Thanks!
Lundie