Download AutoHotkey, and I'll write you a little script.
Will be no problem at all
Official download Link : http://ahkscript.org/download/
I'll just compile it as .exe for you much easier
Okay here it is:
Download
File size: 1.1MB
Virustotal (Virus Checker)
Source Code
As you can see in the file name F1 starts the script and F2 pauses/resumes it.