Help with new Mac server install for CWP

[FMPHPguy]

We have a CWP website that is successfully hosted remotely. We have a brand new Mac Mini Server with FMS 12 installed. Everything seems to be jiving correctly, API calls work, etc. We are moving this site to our internal server for modifications/testing. However, throughout the site, the previous programmer(s) used a lot of $_SERVER['document_root'].'/PathToIncludeFile' syntax to specify includes and requires. This is not working properly on the internal server. When the $_SERVER['document_root'] is called I get this:  "Failed opening required 'cms/db_cms.php' (include_path='.:/Library/FileMaker Server/Web Publishing/publishing-engine/php/mountain lion/lib/php')". As you can see, the include path is completely wrong and looking into the FM install, not the website root. I have spent many hours trying to resolve this issue. Any help is much appreciated. Thanks!!