To create additional domains on your account, log in to the control panel, either directly at https://(servername).hmdnsgroup.com:2222 or via the client area under Services -> choose the control panel link from the dashboard there.
From the main control panel dashboard, choose "Domain Setup" under the Account Manager group of options.
Select the "Add New" button, and input the new domain name in the Domain field. The default options will be fine for additional domains unless there is some reason to limit them, either in transfer or disk usage (generally, this is not the case). If the new domain will need SSl, CGI, or PHP access, ensure those options are ticked. Choose the Create button, and the system will begin the setup of the additional domain. When the creation is complete, a message will be generated and can be retreved by clicking the user icon at the upper right of the control panel dashboard and then selecting Messages.
The nameservers for the new domain should be set to those specific for the server it is on when it is ready to go live.