I want to buy ~$650 air ticket. I have 50k+ points.
I want to use only 25k points for this purchase and pay the rest with cash. (This is not how engine works. It takes 25k points for $500 credit and then 15k more points to cover remaining $150.)

Anyone think of way to temporarily move away 25k points (by buying refundable? ticket/hotel/whatever, transferring to family member/different card/etc.)?
This is to remain only $25k in the account and apply only these points to the purchase.