hmm ... this isnt easy to answer. In theory it is possible, but you have to tweek and trick a lot.
You cannot use bone animations on a Multimesh. You have to incorporate the animation directly in youir vertex shader.
I have done it with a special data-texture. I baked the animation frames into this texture. With the custome property of the multimesh you can tell the vertex shader wich frame to use. The shader then transforms the vertex with the frame data in the data-texture.
So it aint easy but doable.