http://www.ultimate-guitar.com/forum/showpost.php?p=21234847&postcount=2

I just ordered a used Frontman 212R from guitar center and it will be here in a few days. As its used, I dont mind drilling some holes in it and
installing some new jacks to help with what I would like to accomplish.

The manual I downloaded about the Fender 212R is very sketchy to me, in that M makes it sound like you can hook up another head amp to the 212r and just use the speakers and not the 212 head. 

The above photos show a stereo jack with leaves that can lift up when a jack is inserted. If I were to intall one of these in the 212, and hook up the 212 amp and then the speakers to the proper poles......you can use the 212 like a normal combo amp........but if I hook up other wires to the speakers only and you put in a speaker wire male jack
( not guitar wire cable, I learned that much ) then I could run the two speakers from the 212 back to the extension out jack on my Vox AC15C2, and use the 212 just as an extension cab ??

Any help with what parts or wires to buy would be helpful, and I appreciate the help very much.

Thank You all very much !!!