You would need 3ds to blb to convert it, and even then it has to be fixed up some more.
The thing about making bricks is that it's usually done through text, not a modeling program(only for some really complicated stuff).
Destiny has a BLB editor that allows you to see the brick you are making.
Soba says it takes a while to figure out how to do it, and I believe him.
I took a look at it myself, and I do believe that you have to place down every vertex for that brick in the blb. file, then you have to specify the collision areas.