subdomain processing with IP based virtual hosts?

[vulcand4]

I'm looking for a good solution for hosting subdomains with IP based virtual hosting instead of name based virtual hosting.

I have an IP address from which I'm serving up SSL based web content. Because I'm using SSL, I can't use "NameVirtualHost".

I need to serve up pages from www.mydomain.com and different pages from admin.mydomain.com.

I've tried using mod_alias to redirect a request for

https://admin.mydomain.com

to something like

https://www.mydomain.com/admin/...,

but the redirect only seems to look at the portion of the URL that comes after the domain, not the domain itself. So it doesn't seem to be able to see that the user has requested admin.mydomain.com vs.

http://www.mydomain.com.

Any clever thought on how this might be done?