1. Add a switch or few to the dedi server binary a3server.exe -client=IP -port=PORT -hcpass=PASSWORD
2. Put hcpass = PASSWORD in the server cfg, I set allowHC=2 (how many HC are allowed on server, 0 for none)
3. Server runs checks on all clients currently for cdkey. Let cdkeyless clients connect IF they provide hcpass and pass a HC test (http://pastebin.com/nKHxyLNr) or hasInterface, or simply generate a RSA public/private keypair authenticating the HC as genuine..
4. Server runs disablesimulation and disableinput on each of these HC connected clients (or via special NEW undocumented command)
5. If you want to be super anal you could do hcallowed=IPaddress and only HC from these IPs could connect including localhost (127.0.0.1)
6. Server spawns HC in as a bird. If the Arma 3 dev-stable birdflu crisis is remembered by anyone, it should be noted that it's impossible to change units after being a bird..
An alternative solution is offered in this document for AI pref in general (distributed AI processing): (Link fixed)
https://drive.google.com/file/d/0B3VdHnk7BX1BUGtMRmMyRDRza1U/edit?usp=sharing