I think your describing something a little different.. do you have a pic? Are they thewire pushrods that run the full length from servo to surface and there is a plastic tube that fits over that like this
http://www3.towerhobbies.com/cgi-bin...LXPJX9&P=7

... Or.... Is it a plastic tube in a tube type deal with a short piece of 2-56 threaded wire at each end located in the inner tube?
like this:
http://www3.towerhobbies.com/cgi-bin...XFU92&P=ML


Either way you will want to support them as oldtyme says or the rods will flex under load and you will get very little if any movement out of the surface being controlled. Usually it's easier to make your own supports out of some lite ply or even thick balsa as they can customized to attach ot whatever is needed as the rod travels back through the fuse. During building you could even plan ahead and drill small holes in the formers to accept the pushrods being sure they run a straight line from servo to control horn.Mike