If your server has CPanel, then from its new versions it can add wildcarded subdomain like you wish by just adding regular subdomain from Cpanel client interface, you can add there subdomain *.mydomain.com and Cpanel will add apropriate record to apache conf file. If you dont have Cpanel server, then you will have to edit apache conf file manually if you have root access or ask your host to do this.
First, you will need root access of the server. If you are on shared server you will need to update your host to make this changes. If you own your dedicated server locate httpd.conf file. If you are not sure about exact path you can use locate command: locate httpd.conf Then open the file in editor (vi, pico etc.) and search for your domain's entry. There will be one entry like ServerAlias www.yoursite.com.. Just edit this line and save it. Do not forget to restart Apache. Kailash
@Kailash, i can't find httpd.conf in /var/www/vhosts/domain.com/conf/ just httpd.include Now i read a tiny bit about vhost.conf Should i create >vhost.conf or >httpd.conf and all i need is ServerAlias *.mydomain.com, right?
I believe you are using plesk so you do not need to create any new file. Just edit httpd.include and search for ServerAlias in this file and then make the required changes. Kailash