samba - Mar 2008 - winbind, AD on other network an machine accounts

Hello,

we have a network with Xp Clients and AD.
On a second network we have XP clients Redhat linux servers that run 
samba. Between the networks there is a firewall.

Now we would like to authenticate the XP clients in the linux network 
against the AD.

As far as I did understand it should be possible to use winbind to 
authenticate users from the samba server to the AD.

What about the machines ? Can they also be authenticated against the AD 
? When I connect a new machine to the second network does winbind 
register the machine into AD ?

Thanks
Andreas