Punycode is used to encode internationalized domain names (IDN). This guide will demonstrate how to convert a domain with special characters to punycode so it may be added in cPanel.
The first step will be to use a tool to convert the domain name. Once such can be found below:
Simply input your internationalized domain name here and click Convert to Punycode. You can now take the converted text an input it in WHM's Create a New Account section or by adding it as a parked or addon domain in the cPanel Domains interface.