If you are attempting to setup a wildcard DNS record for your domain that resolves to your Dedicated IP address, this needs to be setup within your domain DNS manager, and not within your Hosting Control Center. To modify your Zone Files, you will want to refer to the instructions provided in the following URL:
Here’s the kicker. For every site that you create you have to manually add a subdomain in the GoDaddy Control Panel. Had wildcard subdomains worked on GoDaddy this extra step wouldn’t be necessary. Read below for the steps.