If you want to use your registered domain sitebuildern so you first need to point it to your control panel. Start by logging in to your control panel so you come up here:
Click on the SiteBuilder icon, you will continue up to this page, press the "Edit / Manage"
This is where you choose to point your domain to sitebuildern so that it becomes the primary, what you need to do is select your domain in the list where it says Map Domain which you can see here, we have chosen test.mhdemo.se:
When you press the "Map", your domain will be added to the list as you can see below:
The domain is usually automatically set as the primary, if not then you just need to click on "Make primary" so your website will be published to your domain.