Log into your WHM (WebHostManager)
Go to “DNS Functions Edit DNS Zone” or in the search box, type “Edit DNS Zone” and click to open the page
Select the Domain you wish to edit and click on “Edit”

Scroll down to “Add New Entries Below This Line”
In the first field, enter the prefix/first part of your custom domain (abc, maxcdn, or whatever you choose… do NOT enter “abc.mydomain.com”)
In the second field, you enter the TTL, usually 14400 as a default
In the drop-down menu, select “CNAME”
In the last box, add your temporary CDN domain “zone.company.netdna-abc.com”, you MUST suffix it with a period/dot.
Scroll to the bottom and click “Save”