Anyone knows how to connect the web interface of the ants to a domain ie: ant.mydomain.com
Uh yeah same way you would with any other device. You need access to the domain server records and just create an A record with the IP of the device.
Ok so if they are all on the same network router, would i have to set a different port for each?
Whatever you are planning, don't even think about opening ports up through your router to the miners on your network. Not only will your miners be compromised, your entire internal network will as well.
Minimum you want to do is use a VPN into your network and manage your miners that way.
I think you can use NO-IP.org. I use them for internet access to myIP cameras at home