HostGator does not allow you to edit the necessary information for your domain name if you are not paying for a hosting account with them. You will then need to start a live chat with HostGator support and ask them to do the following for your domain name:
1: Point A record to 220.127.116.11
2: Create a CNAME for www which points to the domain
HostGator does not
Please note that YOU DO NOT need to pay for hosting for this domain as we act as your host. Confirm with HostGator that you are NOT paying for hosting for that domain name.