How Can I Get A Page To Display On A Subdomain Of My Site?

Ok… I’ve been beating my head trying to figure this out, so I’m just gonna post:

I currently have WordPress installed on a root domain like www . mydomain . com. I wanted to have a specific page that was essentially hidden from the rest of my site and only linked to through my advertisements, so I created a subdomain like subdomain.mydomain.com to host said page.

My question is this: How can I get this page to display on the subdomain?

I recently came across this plugin called WP Subdomains, which looks like what I want, however, the plugin requires that you map the subdomain’s document root to your current WP install. Unfortunately for me, this process seems quite complicated on a shared grid server from Media Temple. You see, when I set up a subdomain on my server it creates a whole new document folder just as if I were setting up a brand new domain. I looked through the Media Temple knowledge base, but it seems like the documents relating to my issue require things like deleting folder structures and rerouting directories through SSH. That sentence is greek to me.
I guess ultimately I’d just like to know if there is an easier way to do this, or if someone could point me to a good tutorial that can walk me through it? Any input would be appreciated! Thanks.