PATH_INFO and server working in CGI mode

Permalink
Hello,
I am trying to install C5 on a web server that is running php5 as a CGI.
The sysadmin of the server told me that this variables doesn't work and I should use
$_SERVER['SCRIPT_FILENAME']
$_SERVER['SCRIPT_NAME']
$_SERVER['DOCUMENT_ROOT']

Can I change something in the code or change the hosting.
I hope that first is possible.
If you need phpinfo:
http://mts-bg.com/php_info.php

All the best!
Bobby