Custom path for multiple domains to point to a singe folder

I have an application that is essentially a template file for CMS/DB driven websites which runs about 100 different websites, all from a single code base. I need to be able to configure all of those domains to point to a singe folder, preferable inside of the public_html of a parent host. i.e. home/events/public_html/summit for summit sites, home/events/public_html/think_tank for think tank events and home/events/public_html/dinner for Dinner events. The reason it is preferable to have these different site templates inside of the master site’s public_html is that there are common function/class libraries, so it is convenient to be able to use …/libs/func.lib.php etc. in the child templates.

Does anyone know the easiest way to accomplish this?