Mac,
I'm not sure if I get your exact meaning. If you want to disable "Pause" completely I don't think that can be done, but others may know different.
If you want to have FS continue processing while you're doing something in another window that's easily accomplished. In FS9 just go to Options, Setting, General and uncheck the "Pause on Task Switch" box.
As I write this response my FS is continuing in mid flight and that's how its done.
I hope this helps, sorry if not...
Best,
-Russ