[Samba] Samba with AD Authentication Backend

[xpto 007]

Hello guys,

Please help me if you can. Has somebody ever managed to configure Samba PDC
to use AD  as an  authentication backend, i.e,  like an ldap backend.

I'am trying to build a system where Samba is my PDC and I want to
authenticate AD users in my Samba domain. I do not want to add Samba to AD
domain, and I can not use an Ldap Server (like OpenLdap).

Is this possible? What do I need to do?

Please help me.

Thanks in advance