I've seen my search in the forums "multiple workgroup"  a few other posts.   I don't think this can be done.  Let me know if you find the solutions.

I have Agents who support multiple languages at the same time.  The text in the admin console goes with  each workgroup not queues.  So I think our only choice is to implement our own client to handle the multiple languages by modifying the Fastpath Web Chat client.  Then the products and languages are setup at the queue level.  This makes routing that much more complicated.