It may be easier to convert the pair of models into a single model and rig it.  You can do it with three bones - one for the frame, and a polygon group for the frame; one placeholder bone in the middle, to make sure the door bone does not deform the frame bone (may be another way to do this but that's what comes to mind for me); and one end bone for the door itself, with Bend turned off.  Hide all the parameters for the middle bone, and all but "yRotate" (twist) for the door bone, and it becomes fairly idiot proof.  You can look at the lounger chair in my freebies for an example of this, the foot rest is rigged this way.

To make the various channels hidden, you edit the CR2 once the figure is rigged and look for the blocks of text for each bodypart, and change "hidden 0" (false) to "hidden 1" (true).  Make sure you back up the original before you start hacking around in the CR2.  Also be sure to disable Bend for the door bone, so the mesh will not deform, only rotate.

My Freebies