Check out a machine shop. They probably have what is known as a heli coil. This is something similar that is shown in the links shown by hardwarz. If they have, the machinist could build the 3/8 inch offset cable guard (rod) that you need. Make sure the rod is not larger than 3/8 inch out side diameter because if you put a slide or cable roller on it, these parts fit a 3/8 rod. If they have a rod that is (cold rolled steel) this is very smooth. The threads on the rod have to protrude out of the bow to be able to put a thin lock nut on it. The reason for the lock nut, when off setting the rod for clearance, the nut is tightened to keep the rod from moving. The rod has to be long enough that when you come to full draw, the cables do not come off the end of the rod. An inch and a half longer should be acceptable. This will allow for the extra wideth of a slide or roller, plus a bit extra if over drawing the bow. Best of luck.