So here's the situation:
My company is selling a website management platform called Cola. It's basically a CMS with integrated eCommerce, but made to be super user-friendly and built around a fine-tuned deployment process to make it easy for clients to get up and running and comfortable with the system. As part of the seamless deployment process, we are providing and managing hosting for all of our clients. We've purchased a dedicated Linux server running Red Hat Fedora Core 2 through GoDaddy, have 4 IP's on it, and have full control via Plesk 7.
Now ultimately what we are doing for each client is changing their domain name's name servers to point to us and setting up a hosting account around that. However, in many cases, clients want to keep their old site live until the new site is fully completed. During this time, we need a way to access their new site under development. All of our clients are on shared IP's, so going direct to the IP doesn't work so well.
We decided the solution to be to register GotCola.com, and give them a specific subdomain (ie. todd.gotcola.com) to use until the site is ready to go live.
I've found that I can easily create subdomain hosting accounts in Plesk, but it does in fact create a whole new hosting account. What I want to do is an entry for the subdomain in the DNS settings for GotCola.com and have it point to the hosting account for the actual domain. For example, I want todd.gotcola.com to simply be a pointer to the hosting account for www.todd.com
I'm pulling out my hair as I wade through CNAME's, A's, Master/Slave DNS, and a couple dozen other things I haven't the faintest understanding of, trying to figure out how to make this work.