Additional Domain added to Intermedia Account

I use Intermedia for hosting. They have a knowledge base article for people to use to set up multiple domains on one account but we are required to use our own PHP ([login to view URL]) I have tried to get this working, but it is not going anywhere fast. I need someone to add the required PHP to the required index file so that it automatically routes new domains to a subfolder on the host, rather than the route directory. This is not like cPanel where you can add domains and it will automatically forward to a subdirectory, this needs to be done manually but I cannot seem to get it working. This is the code they recommend using (but does not work): [login to view URL]