EXEC master.dbo.sp_addlinkedserver @server = N'LDAP', @srvproduct=N'Active Directory Service Interfaces', @provider=N'ADSDSOObject', @datasrc=N'adsdatasource'
EXEC master.dbo.sp_addlinkedsrvlogin @rmtsrvname=N'LDAP',@useself=N'False',@locallogin=NULL,@rmtuser=N'domainLDAPQuery',@rmtpassword='########'

select displayName, userPrincipalName
from 'LDAP://domaincontroller.domain.com/DC=domain,DC=com'
where objectClass = 'User' and objectCategory = 'Person'