Calculating vat on freight

Hi,

I would appreciate if any of you can help me achive the following.

My SAP client wants to add the Freight Charges in the purchase order. But this Freight should be added to the subtotal 1(Basic - E.D+HCess+SHECess)  and then the VAT should be calculated on the Subtotal 2 (Subtotal +Freight)

EG:

Basic Price: 7560

E.D 12%     :  907.20

H.Cess 2%:    18.14

SHE Cess 1%: 9.07

Sub Total 1: 8494.40

Freight         : 242

Sub Total 2 : 8746.4

Vat 5% :         437.32

Grand Total: 9184

Thanks & Regards

Ashok