Pay 2 Vendors from 1 Purchase Order

Based on the searches I have done, this appears to be the opposite of what everyone is trying to do, but I want to pay 2 vendors from 1 Purchase Order. 

Here's the scenario:

I have a Stocked item that I will purchase for $100

When I post the invoice, I want to pay the Invoice account on the PO $98 and I want to pay a separate vendor $2.

It looks like this would work if I could distribute the amounts, but I can't do that with a stocked product.  I would like to do this without customization, so if anyone knows of something I might be able to use or something that works similarly, it would be much appreciated.