Well actually mine was not an advice, just a simple consideration
FeiHongJ suggestion may work but it seems to be a little complicated in my opinion
However you can simply attach the vertices of the cloth to the bones of the body
Normally it works fine,using vertex animations for special cases only.
You can not yet mixed up vertex and bone animation in the same animation sequence but you can mix them up in the same animated file
This is what I did at least