I'm not sure CDG is a good destination for bmi. They need to tie into delivering passengers to hubs, and I doubt that KL/AF would agree to them codesharing into CDG when they're trying to route traffic through AMS.
That said, it seems LH aren't exactly being constructive in enabling transit on the existing BM routes to FRA/MUC. Given that they pulled the rug out from under us at very short notice in March 2009, I would have hoped they could have moved a bit quicker. Maybe their turmoil over SCORE and the 4U integration isn't helping.