I looked for the existing ldap plugins. I thought there was an extras version but I could not find it. The official 3.1.6 version should have enough fields to get any directory service working. I would be willing to write a script to try and prefill some of the fields if they are available from dns.
Just a warning... I have no way to test AD nor do I want to mess with anything Windows related. Just ldap on my end If it works with AD, great.
If you make it idiot proof, somebody will build a better idiot.