Probably not the best title, but I am not sure how to describe in a few words.
Alright; I wish to have an "overall" domain to view my websites in browser. Like I would like to have, eg. testdomain.com to work as my "overall" domain, so I could access the sites I'm hosting like "mysite.com" - on "mysite.com.testdomain.com" (or somewhat near).
I need to locate the corresponding website, based on that subdomain, and serve it to the browser. Much like i can FTP into "testdomain.com" with the user "mysite.com" to access the FTP account.
Is this possbible and how can it be done? I hope I meane this clear.