PID output to a variable

[prometheus]

I am trying to use a PID loop from the WPI library to control my robot drive in the autonomous mode. I don't know how to make the PID loop output to a variable that I can set to the drive speed. I tried making a bogus victor and setting a float variable equal to that value, but I got an error when I built the code saying "cannot convert `Victor*' to `float' in assignment". Any ideas out there?

Thanks in advance,
will