Hi Jaime,
When you use the New Charge/Credit, the system will post a document with the type as Other receivable/ Other payable based on supplier charge or supplier credit you select.
This is will showing as 'Open' status in your supplier account monitor and you can 'CLEAR MANUALLY' and select an invoice which you want to clear with this new charge/credit posting.
Try it in your internal system,this should work.
Thanks
Lokesh Sharma