easiest way is to use a third-party cpanel theme that already has it integrated. eg. cpanel xp2004 from cpanelskindepot.
In my stdheader file, I added a simple link called "Billing" that would take a user to our MBill login page. *IF* every Cpanel user's acct was set up by a current version of MBill, you could conceivably use their CPanel contact email address and send it along to "pre-fill" that part of the MBill login. In fact, if you force MBill to use the user's MBill login password as their CPanel acct password, you could conceivably put them right into their MBill account...
I also created a MBill user dashboard that lists all of their domians, and all of their hosted accts and gives them links to login from MBill to their CPanel, or to update nameservers, or to login to other services I bundle, etc... I think I had posted that hack in the MBill forum a while back...
I also created a MBill user dashboard that lists all of their domians, and all of their hosted accts and gives them links to login from MBill to their CPanel, or to update nameservers, or to login to other services I bundle, etc... I think I had posted that hack in the MBill forum a while back...