Hi,
You have to pay to the vendor who does the QI inspection also, correct?.
Create recursive BOM for the material, where you can maintain child and parent material the same. Now, create the subcontract PO for the material and follow the standard subcontract procurement procedure. Maintain the PO price accordingly. You can send and receive t he same material. Also, here, you can check the stock provided to vendor and other details.
After receipt from QI vendor, with results, you may create a return PO / MIGO - return delivery for the QI failed materials and send the materials back to the original vendor.
Regards,
AKPT