Domain Mapping

I have and addon domain that I installed this on. But when I click on any sites in the multisite install it takes me to the main domain on the cpanel account

What I was origanly trying to do is point m. subdomains to my multisite install where I am building mobile sites but same thing when you type in the m. subdomain it resolves to instead of the addon domain on that cpanel so thought this plugin would do the job.. Any help