Support

Admin Tools is irrelevant to what you're trying to do.

First, you'd need to set up your web server to respond to all possible subdomains. This is something that is done in the server configuration to which PHP (therefore Joomla and Admin Tools) have no access to.

Once you do that, all possible subdomains would respond with the same content. You would have to write custom .htaccess code to redirect the non-canonical subdomains to your canonical subdomain. This is not something Admin Tools will do for you and it's well outside the scope of our support. In fact, it's something you shouldn't be doing in the .htaccess. Since you're already modifying the server configuration to allow all subdomains to be responded to by the same document root you should write your redirection rule in there, not the .htaccess file. This has very significant performance benefits (the server configuration is read and parsed once, when the web server starts, whereas the .htaccess is read and parsed on each and every request even if it's to a static file like images, CSS and JavaScript files).