There's already a quite easy way to use bvh files for models in MED.
You need the free tool bvhacker to optimise the bvh file for your purposes.
Then you need fragmotion to combine the model with the bones and export them as a mdl7 file.
In MED you can do all the optimizing and fine-tuning and so on, there is only one issue:
when exporting from fragmotion, it seems that the model is set at a higher position within all frames except the first one!
You can solve that by adding a new bone in MED, let's place it between the feet, and connect it to the main bone (the 'uber parent') of the skeleton.
The disadvantage of this step is that you loose the 'bouncing' movement of the whole body what you have to re-'animate' frame by frame.