Samba4 + Kerberos cross-realms + ldap

[Mauricio Tavares]

      Quick and easy question: I have a network which already has its
own kerberos + ldap servers running and I want to setup a samba4 box
as AD. So, from conversations here and on irc, the best thing to do is
to setup the samba4's built-in kerberos to do cross-realm
authentication with the other kerberos server. Now, how would those
crossed users look like in samba? Or, how would they be created in the
samba4 ldap so they would have, among other things, a local home
directory (or wherever the homedir; it just have to be in a place
samba can find, know what to do with it, and do it) which would the be
exported?