advice on setup

Hi, i use CWP currently and have it running, but i want to get some advice on how to best setup my systems because currently i have limitation that im not sure how to get around.

System at the moment

• One physical server that is running windows hyperv server
  1st Hyper V is CentOS running CWP, which has domains connected to it and websites etc
  2nd Hyper V is Debian that is running a game server
  Single IP that i have registered a Name Server on that points to this IP and is captured by the CWP system.
  CentOS, Debian and HyperV server all run on the same local IP range 192.168.*.* and share the same WAN IP
  The firewall infrastructure is all UniFi, not sure if that helps or not.

My issue is that I can't seem to allocate a domain to the Debian system, i want it to actually be a sub domain of a domain hosted by the CWP, but I'm not sure how to do this?

I'm thinking that my system as a whole isn't setup to do this well in the future.

for example, i may want to have another domain that is another VPS running linux with a web server, but I'm not sure how i would do this in this setup either?

It's nearly like i need some sort of routing before all of this to direct it all?

any help would be hugely great!!

You have to ask it on another forum about Hyper-V virtualization This forum about CWP and CentOS and not about Windows or Debian.