[Samba] Default AD user lookup string

[Jason Gerfen]

Is there a way to change the lookup string (correct me if I am wrong 
here) regarding the schema attribute Samba uses for AD authentication?

Not if this is accurate but it seems the AD lookup queries the CN 
attribute within an active directory user account.

My problem is I have legacy user accounts which under the CN attribute 
have not just their login name but their last name as well: ex. CN=John 
Doe,OU=Users,DC=domain,DC=com

Is there a way to specify the schema attribute Samba will use for AD 
authentication such as the 'principalName' attribute?

Thanks.

-- 
Jas