This article will assist you in registering private/custom/child nameservers for your domain from the DirectI control panel. Please note that DirectI is one of the channel registrars of AccuWeb Hosting.
2. In the upper-right corner of the control panel home page, click on your user name. Click on the My Account link.
3. Under the Manage Orders menu, click on the List/Search Orders link.
4. Locate and click on your domain name.
5. Click on the Child Name Servers link. Enter the child nameservers you wish to enter along with the IP address. E.g., If your domain name is "testDemo.com" and you would like to use nameservers like ns1.testDemo.com and ns2.testDemo.com and point them to your hosting service (such as VPS), then you should enter nameserver names under "Host Name" text boxes and IP address of your DNS server under "IP Address" text boxes.
6. Click on the Save button one by one when you complete the entries.
7. Once the nameservers are registered, you can use them for your domain. For that, you just need to replace the current nameservers with new ones. You can find its detailed instructions from this URL.
Note: The changes made in DNS records require 24-48 hours to propagate around the globe.