[Samba] idmap with NT4.0

[Meli Marco]

Hi all,
I have read about this but is not so clear if I can or I can not map windows
user to an LDAPbackend structure via winbind instead they are store in
idmap_winbind.tdb file, so I can connect by another samba domain server with
the same uid/gid, I know that it is transparent for the user, but it is
important if I want to replicate data to onother samba member domain and
keep the same user database.It is all in the same LAN and I can not to avoid
the Nt server for politicaly reasons, it always keep the SAM. 
There a guide to do it step by step?
Thanks a lot,
Marco.