Pointing a domain to another /domains/example.com/public_html without domain pointers

I need to get a domain redirecting to the public_html folder of another domain for Drupal multisite set-up, but I don't want to do it with a domain pointer because then I can't have a seperate e-mail account for example. I tried looking at the httpd-vhosts file to see if I could change the entry there, but DirectAdmin apparently doesn't store the entried there...

How would you recommend I set this up?

One way to do it would be to set up the second domain normally, then use a redirect in the .htaccess file to redirect only the http.

Here's how I do it in an .htaccess file in public html to redirect domains.nobaloney.net to my secure site for domain registration using a shared certificate:
Warning: do NOT buy domains from this site; we're phasing it out and have raised our prices so no one will use it.

Jeff

I don't want to redirect users; the visible domain should not be changed at all.

Visitors should go to http://sixstarproperty.com for example, which is usually linked to /home/admin/domains/sixstarproperty.com/public_html, but that link needs to be changed to /home/admin/domains/my-drupal-site.com/public_html so that I can use it in the multi-site set-up.

I am not sure but using a CNAME might do it.