iProc - v11i - How do you make the buyer's pcard default

Example -

I want an Admin who does not have a pcard to enter requisitions for my department.  How do I make the po pull the pcard for buyer who is creating the po? 

(Assumptions - supplier site is pcard enabled, supplier does not have a supplier pcard, the category is iproc enabled, buyer has been set up as a pcard buyer)

Thanks for your help.