How to do the following with subdomains

[streamservice]

Hello,

I want to add for some domainnames the following option for subdomains.
[sub].[domain].[tld] -> /home/[user]/domains/[domain].[tld]/public_html/[sub] (not in case it is www.[domain].[tld]). How can I do that?

[jlandes]

http://www.site-helper.com/subdomains.html

[streamservice]

That is a system for per subdomain, I need an option for all directorys (more than 250 and raising). So subdomain by subdomain isn't an option. I know it is possible with apache, but manually editing the apache config files is also not an option (because DirectAdmin will rewrite it when I add a domainname).

[streamservice]

Anyone an idea? It should be possible, but somehow I cannot figure out how this can be done in combination with DirectAdmin.