That's pretty much what I do - cut out a 'groove' from the carpet / underlay and put trunking in that - make sure it's well stuck down to avoid accidents..You could put a small channel of trunking underneath but it would be alot of work and with a cable of those dimensions I'd be inclined to either stick it behind the gripper track or remove a little underlay and put it in front of the gripper.
You can get skirting with a channel relieved from the back side and I suppose the same idea could be used for a traditional wooden door saddle but once again alot of work to hide a few feet of small cable.