Shipping Fees in Purchase Order ?

Shipping Fees in Purchase Order ?

HI
When I make a Purchase order, I add a line for the Shipping and choose a different COSG than Inventory for this line.
However, when I receive the order, I cannot <receive> the shipping item (which is ok) but, all my Purchase orders remains Partially Recived.
Is there a better way to manage the shipping fees I got to pay from my suppliers on a purchase order ?
Should I distribute the shipping cost on the cost of each item ?

Thanks