samba - Oct 2004 - Is it possible to specify read only by netgroup for hostname entries?

I'm not seeing any way to do this in any of the documentation, but...

We have NFS shares that are equivalent to our SAMBA shares and the NFS 
server can be set to share rw to one netgroup of machines and ro to 
another netgroup of machines (our lab machines).

Is there any way to do that in SAMBA?  It seems that hosts allow can 
specify a netgroup of machines, but there does not seem to be any way to 
specify a read list or something like that for machines, only for user 
names or netgroups of usernames.

Any chance I'm missing something that could make this work?

Thanks very much.

--
David Pullman