A few years ago when traveling on a BA award the ticketing agent let me pay the full amt to UG from a free C seat to F by paying the fare difference from C to F. Does anyone know if a *A carrier would allow the same thing? I am thinking of the *A RTW award from DC and wonder if there is a way to pay to get some of the segments from C to F--I know it won't work with UA, but wondered if anyone had any luck/experience with other *A carriers.