Extra accounting document creation for cash invoices

Dear experts.

I have the following case: A sales order can contain both cash materials and materials on credit. This results in the creation of two outbound deliveries and two invoices. The first invoice is cash (the customer pays as soon as he gets the materials and the invoice) and the other one is on credit (the customer pays according to his payment terms). The accounting documents in FI for both invoices have customer in debit and sales and tax in credit.

The question is whether there is any standard SAP procedure according to which the system (when billing a sales order which contains both cash materials and materials on credit) creates for the cash invoice an extra accounting document that has the customer in credit and a G/L account (for the plant which collects the cash) in debit since the customer pays cash and his account has to be closed. For the invoice which is on credit the system doesn’t have to create the extra accounting document because the customer will pay according to his payment terms.

Can anyone help us.

Thanks in advance.