I would like to be able to give cpanel access to my add-on domains, but such access that it doesn't interfere with my own website.

My add-on domain (icalin.net) is added to my primary website, mgatesphoto.com. I can go to mgatesphoto.com/cpanel, but not icalin.net/cpanel

How do I let icalin.net use it's own cpanel, just as I am using my own?

Going to icalin.net/cpanel is the same as mgatesphoto.com/cpanel. I want to be able to use cpanel on icalin.net where it only affects icalin.net, no other domain. Where icalin.net has limited priveleges (eg, cannot mess up the settings I have on my primary cpanel and won't mess up the site. restricted access to only icalin.net).