Consumption on a Production Order

I have a 'finished' item "Product F" that is made up of 100 "Product A". Product F is made by a subcontractor after I send him Product A (100 per Product F).

I have set up Product F to be a Production Order with a Subcontractor routing, etc. I have to make 10,000 Product Fs (which means I ordered 1,000,000 of Product A).

Normally, I receive all the Product A, allocated it on the Production Order for Product F, Relase the Production Order, Create the PO to receive Product F using the subcontractor worksheet and I am done. However, I have now run into a situation where I only received a partial batch of Product A and need to receive a partial amount of Product F.

What is the best way to allocate my partial receipt of raw materials Product A to the Production Order and create the PO to receive in the finished (Partial Order) Product F product?