I've found myself in an interesting position...basically I have seen this done, but do not have access to the files it was done in, or the person that did it. I have been told that doing this is why we bought Solidworks Premium.
We make RF assemblies, consisting of a radio card, an antenna, and a pigtale connecting the two. The radio card and the antenna are a fixed distance apart (Let's say 4 inches along X axis, 0 on the Y axis, and 1 inch along Z axis), and the pigtale is a fixed length, such as 6 inches. This pigtale is fixed to deal with RF properties, so changing it's length is not an option.
Apparantly there is a mating option of some sort in soldiworks premium that will be of great assistance in doing the routing of the cable in order to use up all 6 inches of cable while mating the card to the antenna.
How I have done it so far is to do a 3d sketch of a spline from point A to B, and it's close enough for some drawings, but I am running into situations now where I need that pigtale to be exact length.
Any suggestions on the best way of doing this? Again, I think there is some feature in Premium that assists with this, but I'm not really sure what I'm looking for.