An easy way to duplicate an existing cpanel account is:
1. Backup the existing account /scripts/pkgacct domaina
2. Change the domain name and username of the existing cPanel account via
WHM >> Main >> Account Functions >> Modify an Account
eg. domain name from domain.com to domain.net and username from domaina to domainb
3. Restore the backup from the original pkgacct using
WHM >> Main >> Backup >> Restore a Full Backup/cpmove file
eg. cpmove-domaina.tar.gz
voila!
