[Samba] Internal DNS Wildcard

[David Cric]

Hi,
I'm running Samba4 as a PDC using the internal DNS. I want to add another domain, so I created one under forward zone (say example.com).

However, if I add a cname test I can ping and resolve test.example.com, but I can't get it to work for just example.com.
I tried adding an asterisk (*) but it won't resolve. Any idea how to get this to work?
Obviously, this is only for internal (network) and not outside (internet).
Initially, I tried getting Samba4 work with Bind 9.9, but every time I try to join a domain as a DC with --dns-backend=BIND9_DLZ I get: LDAP error 53 LDAP_UNWILLING_TO_PERFORM. However, it works fine with the internal DNS...
If possible, I would appreciate any hint to make internal DNS work with wildcards...
I'm running CentOS 6.4. 
Thank you.