Grabbing a value from a library function

I'm just starting out with Arduino, and I'm using Gammon's profile timer library to find the time it takes for my function to complete (Gammon Forum : Electronics : Microprocessors : Timer library (ProfileTimer) - times code on the Arduino). I want to know if there is a way to take the "interval" variable being declared and declare it globally in my code so I can use the value for some arithmetic.

Thanks