Forum Moderators: phranque
Welcome to WebmasterWorld!
It might be easier to simply put all subdomains into subdirectories of one catch-all domain, and then use mod_rewrite testing the {HTTP_HOST} variable and checking for 'directory exists' to 'steer' each requested subdomain to its corresponding subdirectory.
Try a search of WebmasterWorld for "subdomain subdirectory HTTP_HOST rewriterule [google.com]' for more info.
Jim