Trade Operation are not based on PO receipts

Hi

We have 2 costing methods used as follows

• Standard Costing method for the Primary book
• Actual costing method (along with LCM) for the secondary book for analysis purposes

When we create the Trade Operations (for the charges like Custom Duty and Freight), the charges are allocated either on "PO basis or PO line basis" but we wanted to allocate the charges based on the "PO receipt" as with following example

1. PO is created with following details (for the naterial)
   1. PO #123456
   2. Line 1 with "Item X"
   3. "Qty-100"
   4. PO unit price "$10/unit"
   5. total PO price "$1000"
2. PO is received partially with a quantity of "30" with "Receipt # 7890"