Automate the Add Subscription in Plesk as part of a sign up process

The brief is to write a code to automate server set up in the process of signing up someone to my web system Code is needed to automate the process of Add New Subscription hosting I want to be able to have a form that I can input the domain name , default email, client id, and then that sets up a new Subscription and mail account and returns to the site The form will contain the following domain name( url) , Client id Site id username password client email this will be a form stored in session variables I have already edited the Plesk files so the standard folders and index page in plesk has been replaces so that Add new dunscription function inclides specific [login to view URL] page, htaccess page and a /login folder Code is needed to automate the process of Add New Subscription hosting using password and username variables stored setup one email address and set forwarding for all emails to account email( session variable ) I would like the setup to create a subdomain of mydomain so the site can be developed offline as test area until site goes live? ( is this done through a table on the database in a similar way that the URLs are stored? Return to the application process with the client id and site id as session variables so the rest of the process can be completed I need a second script that will do the same as the above but using a subdomain of mydomain only , not using a domain name I need a holding page that is branded coolsites, but has the domain name displayed " this is a holding page for yourdomain com" Flag up in CMS that site is still OnHold I need code to switch the display from the preview ( on hold) to Live - and the reverse Live >> Hold and forwarding to account email