You can easily add a wild card entry for your domain name through cpanel. Here is how you would set that up.
- Login to your cpanel account by using your cpanel account e,g; mydomain.com/cpanel
- Under the "Domains" column click on "Subdomains"
- Under the Create a Subdomain section, you will see the input text box "Subdomain" enter * as the subdomain in there and leave all default settings
- Click on create button