Double multisite

I have WPMS set up on my domain, the structure is set to give blogs as http://www.domainname.com/blog

I would like to do a complete copy of my site in Polish. Is there anyway to do this at the domain http://www.pl.domainname.com etc and then all it’s blogs will be http://www.pl.domainname.com/blog?

Any help would be much appreciated. If you dont think this is possible, a simple no would also help.

Thanks a lot