This may not provide a solution to your question but I want to make sure you’re aware of the simplicity in getting your character into UE4.
The only requirement is to have a single hierarchy skeleton bound to your character. Well, that simplifies it way too much. I doesn’t matter how complicated, grouped or constrained your control rig is, as long as it has a 1:1 joint set up with the bind skeleton. Meaning that you can’t have 8 joints in the spine of the control rig and only 3 in the bind rig.
Take a look at this http://eat3d.com/free/maya_udk_1
It’s part 1 of 3 showing how to get a playable character out of Maya into UDK. The answer you’re looking for is in this video, I hope.
Just ignore all the stuff about default.ini, classes, pawns etc. The main point to pay attention to is baking the animation, deleting the control rig and exporting to FBX.