Supplier Warranties

a) Can we load the supplier warranties?  If so what is the interface table or API?

b) We need to issue a PO when we need to buy warranty from other OEM?  How to load the supplier warranties when the PO is executed from vendor?  Eg: We manufacture a product, but we buy sub-assemblies from other vendors.  We also sell extended warranty for our products.  As part of that warranty we have to buy warranty from vendors.  So we need to issue a PO to the vendor when we buy it from them.