I have never heard of anyone being able to export a monster properly with anything but maya, and even that seems to be a great amount of pain when looking at this tutorial:
http://www.frictionalgames.com/forum/thread-18352.html
I feel sorry for you mate.
If I have to come with anything constructive I would say you could try and download a student license of maya, get opencollada(if you know a better way to do blender to maya use that instead but this is all I know) , import your monster into maya and maybe you be lucky and have it imported properly. then you can export it from maya.
I know this sounds very impractical and has a high chance of failure but its all I can come up with mate.
Good luck!