bigger problem might be getting permissions off the mesh creator ;-).......... are you allowed to re rig in another app?  purely for ones own use ??

here's gruffles (lol I just found him god knows how long he was in runtime)

exported with collada ~ rigging intact fully posable but could do with some tweaking here and there on weight maps (maybe does in poser too I only picked him 'cos theres no morphs ~they can cause problems for me )