Approach 1: Replace the entire CMS with your own custom version of the servlet

This document does not describe how to create a servlet, resources on the web might help you.
If you decide to replace the entire CMS provided with Host On-Demand, you will need to use an HTTP parameter for requests and XML-formatted data for responses. Parameters are supplied to the CMS servlet via an HTTP request, and the response information is encapsulated into an XML-formatted object and returned to the caller.