Not sure about how to automatically format the name but you can rename the VM to what ever you want. The name can be an IP or domain name. If a domain name, it must resolve to right IP so you will need to add a dns entry in your dns server.
Go to “Host systems” in the cloudmin menu and select the host systems option (ie KVM host systems). Click on the host you’d like to change and you can select a DNS domain to add your guests under from the drop-down list.
If the desired domain doesn’t exist, click the add domain shortcut and add a master zone for “domain.com”