Thanks to all who contributed here. I got a lot of responses, and the bad news is I can't do exactly what I wanted to do here.
Several people suggested making a sketch from the logo file using the edge loop tool in sketcher and importing that; I can then scale the sketch when it comes in. Problem with that is that our logo is all swoops and curves and splines. As a result, once I imported the sketch, Pro/E had to assign dimensional values to all these entities and the roundoff error caused them to not be closed, solid forms anymore. So I would have had to spend a lot of time repairing these splines.
So I just saved the logo part to a new part number and increased the size of the logo from there. Not really the best way to do this, but it got the job done.