.c3d motion capture

I’ve been trying to get c3d motion capture data from http://mocap.cs.cmu.edu/ to work in Blender. Jean-Baptiste PERIN’s c3d import script works very well and gives you accurate moving empties, but these empties are unchained (unparented, disconnected, automomous, etc.) that have location IPO’s and no rotation IPO’s. In the vid clip below the cube is parented to a central empty - it moves with the empty but doesn’t turn.