As long as the plug the other end of that jack into the router then all you have to do is plug a cable into the wall into the jack on the back of the 922.
It might be cheaper to do the homeplug thing or wireless bridge depending on how much Comcast is going to charge
Comcast would charge $28 to install the CAT5 plug. Digiblur, thanks for the info, but I'm confused by your first sentence.
Is there a CAT5 plug on the back of 922?
I'm sorry again, but I'm just plain stupid when it come to these types of things.