My software needs to automatically add the domain entered in the "Domain" field.
It may do this by adding a checkbox that when checked will display a domain field for the "main" domain that the new domain will be added too.
This is the domain that will be used to add the add-on domain too.
The software will then do the following...
Log into cPanel
Add the new domain that is in the "domain" field
Install WordPress with Fantastico
Log into WP dashboard
upload, install and activate the selected themes and plugins.