UPS v2.0 (multiple functionality additions)

[vargpr]

I would like to include in the same area where the shipping rates are a box that customer can check if they have their own UPS account Number.
Is this possible?
I was looking in to possible taking one of the rates and making it $0 and change the UPS Worldwide Expedited SM to " I Have My Own UPS Account"

But how would i make it =$0.0?