If you have a service of a dedicated IP, assigning it to both desired domains and subdomains is straightforward.
You need to access the section for WWW domains in the ISPmanager control panel.
ISPmanager 5 Lite/Business
Navigate to ISP manager in the WWW domains section. Next, select the domain to which you want to change the IP and double-click on it. In the window that appears, there will be a field for the IP address.
Opposite this field, you can change the IP to dedicated or shared, whichever is more convenient for you.
The number of domains to bind to a dedicated address is not limited.