Fixing spline length for cable assemblies

We use a lot of external cables to connect our rackequipment. Up to now I've installed the connectors and then added a3D spline based cable in between. I can measure the length of thespline with the measuring tool and it gives me a rough idea of howlong a cable I need. But what I would really like to do is thereverse - create a cable assembly with a 3D based spline with afixed length for the cable. That way I can install one connectorand then route the flexible cable spline so that I can fit theother connector and have an exact length for the cable. Right nowspline length is a hit or miss affair, and we've had to iteratecable length in the real world on more than one occasion.

So can you fix the spline length? Or is this a feature that wouldbe useful in other applications and should be submitted as arequest? How do others design cables like these?

SolidworksAssemblies