Allowing Finance Charges to be applied when receiving customer payments

Rather than having to raise a credit note against the customer invoice for fees deducted by online trading sites before payment is received by us, we should be able to select "Finance Charge" and put the correct amount of these fees in. Currently the only option in the receive payments screen is to leave the finance charge as an underpayment and then process a credit note against the invoice, which is a long winded process, especially if receiving many of these payments each day!