How to modify auto_prepend_file dynamically

Thanks for all for the response. My application work in the Win32 system with Apache web_server and have php.ini directives configurated like auto_prepend_file=C:\OPENFEDRA\apache\htdocs\systemvariables.php My PHP script do not have any include_once() function because the directives of the PHP include the script systemVariables automatically in the code. The question it is: Instead to have auto_prepend_file configurated and to use include_once() in any script PHP, It is possible to have any ather solutions???? Can anyone have same code sample for me to resolve my problems? Thanks for all. ciao Franco.