sp_addlinkedserver 'ADSI', 'Active Directory Service Interfaces', 'ADSDSOObject', 'adsdatasource'

SELECT * FROM OpenQuery
(
ADSI,   
'SELECT title, displayName, sAMAccountName, givenName, telephoneNumber, facsimileTelephoneNumber, sn
FROM ''LDAP://DC=DDDLTD''    
where objectClass = ''User''')