How can we use our company credit cards to pay bills for inventory items that were bought, received, and billed using the purchasing process?

Add'l detail:

Our production managers often need to purchase materials from large industrial supply houses - they pay up front with a company credit card AND issue a PO# to the vendor which we need for our manufacturing process. However, after we receive the item into inventory, we need to do a vendor-bill (they won't send us an invoice - it's already paid by credit card!), and then the system tells us we have a bill to pay (but of course we do not). When making payment, we can only choose bank accounts rather than credit cards (of course, when we sell