How to clear downpayment of higher value than invoice

Question

Dear All,
I'm tryig to establish new procedures at cutomer AP department and one of them is causing me a headache.
Situation looks like this.
- Vendors requests for Downpayment
- Downpayment request is posted with F-47 (value 1000 USD)
- Downpayment request is paid with F110
Now, couple of days later, vendor comes back with an invoice ( only 700 USD)
- Invoice is posted with FB01
- Now, downpayment should be cleared (F-54) againist the invoice - PROBLEM is that downpayment value is more than invoice value.
Question: How to clear downpayment in this situation so remaining amount (1000 - 700 = 300 USD) becomes a regular "Vendor debit".
Objective: I need to clear this dowpnayment in a way which will cause 0 (zero) payment to the Vendor invoice in F110 and remaining amount  can be cleared in the future when Vendor returns the money to the cashier.
Thanks for help - in advance.
Best regards
Tomasz
Vendor will eventually return cash and
Edited by: Tomasz  Gaczynski on Oct 25, 2010 5:03 AM

Answer 1

Ok, I owe you some more explanations:
The "Vendor" is actually a company employee created as vendor. He receives expenses downpayment and comes back with set or "original receipt" slips and summarized expense report which is posted as Invoice. HE HAS TO return the money as no "further invoice" will be issued.
In current process - F-44 is used but I'm trying to get rid of it.
I'd like to have a scenario like this:
- Downpayment is paid
- Employee comes back with sumary expense which is posted with FB01
- Invoice is cleared against downapyment with F-54
- Upon payment run, invoice is cleared (zero payment is maid) and Vendor account is debited with remaining amount
- Employee returns money which are posted and cleared against remaining, original downpayment
- Emplyee (Vendor account) balance is now 0.
- Case closed.
Now, like I said - they clear everything with F-44 and case closed.
I need to come up with something using F-54 (maybe with transfer posting) as in future, this process should be automated and F-54 is easier to use than F-44.
Any ideas? Thanks