Usually, we do not advise allocating dedicated IP addresses beyond one per hosting account however it is possible to add multiple IP addresses using sub-domains or add-on domains in cPanel should you require it. eg. for multiple SSL certificates on one account.
Please contact us for further enquiries.
For customers with their own dedicated server, the following article describes the process. As it's a reasonably advanced technique, please be sure it's what you really want to do. Ideally, we'd advise sticking to the one IP and one SSL per hosting account rule.
http://docs.cpanel.net/twiki/bin/view/AllDocumentation/WHMDocs/DedicatedSubdomains
© 
