MP3 Export Add-On

Once a year I format my computers and re-install everything (OS and programs) fresh, well it's that time of year again, so here are a few questions for anyone that has done this:

How do you save the MP3 "Add-On" registration key you purchase for Sonar 3 before wiping out your hard drive?

and

Is there a seperate Registration Key for it or does Cakewalk keep it on file?

Thanks in Advance for any replies if you have gone through this procedure before!

Reckert