I'm trying to book a somewhat complicated international itinerary in which I am traveling on business but making a stop for vacation along the way. My company will pay up to a certain amount for the ticket and anything beyond that I have to pay for. So basically, I need to put part of my ticket on my corporate credit card and the balance on my own card. I called the Plat line and they said this isn't possible.

Would it be possible to buy a NW gift certificate for the amount that I need and then apply that to my reservation and pay the balance with my corporate card? Does this sound like a feasible work-around or am I missing something?