CAT Rigging bones constraint for root motion


I have this issue, we want to give a constraint to a bone (NewRoot in the screens) so that it will follow the bone (root in the screens) only on movement (no scaling or rotation) when animated. And we need to keep the hierarchy as it is in order to make it work on Unreal Engine 4 4.10 for root motion.

In the first screen is what I have now :

The second screen is what I’d like to have :

Here is the link to the file :

If you may help me with this topic, i’ve been trying to find an answer but didn’t succeed.