Please keep in mind the following is just an example and demonstration of how the script I've written could be used. With no regard to error handling and input validation.
First an end-user navigates to your index.html.
When navigating to the hosting page a customer is greeted with the following:
The end-user fills in their details along with the domain to be registered.
Upon pressing the Register button, the data filled into the form is handled by a PHP script.
On the front end, the customer is shown a confirmation page.
The virtual host has now been created successfully along with the user account.
If an FTP service is installed and configured the end-user can also access its files through FTP.







