Supplementary Invoice in SD SAP

Have created one proforma invoice & transferred stock to my branch / depot at Delhi. This is my mother invoice with MRP, say, Rs. 100/-. Now the MRP is increased from date: 01.08.2007 with Rs. 107/-. I need to pass on the additional Excise duty for difference amount Rs. 7/-.
Is it possible to generate supplementary invoice in SAP SD module?
If yes, then how to create it? Please help me how could I resolve the problem.

To the best of my knowledge you cannot generate an excise invoice without reference to goods movement.
If you want to ensure the customer is debited for the relevant amount, please generate a credit memo and an excise JV to ensure that the relevant accounting entries are passed. However tracking is possible only through text fields.