Receipt against PO

We want PO to show seperate lines of freight paid to supplier. This is requirement of Custom Authority for different rate on items and freight and packing charges. These charges are amount actaully mentioned by supplier.

But at the time of receipt we want to take these charges as part of item price (prorate). How can we do so without using average cost option. 

Is there any type of tax which is lumsum amount based.

Regards

Sajid