Direct sales Scenario configration in SAP....

Dear Friends

The scenario from the customer is like this:

1) End user orders directly on Supplier. Customer will not know about this order

2) Supplier supplies the product to the end user.

3) Then sends the Invoice to Customer. Customer will know about the transaction only when they get this invoice from supplier.

4) Customer does not maintain any data of the above transaction. They just make Direct Sales Invoice to End user based on the Supplier Invoice details.

5) While creating Direct Sales Invoice, they enter both nd user details and Supplier details along with product details in the same screen.

How can we configuare this scenario in SAP??

Pls note we can not user Third party sales as there is not sale order craetion nor customer wants to create the sale order...

Rgds

Anis