If you really can't use an include, although that seems very odd, I suppose you could always use the backtick operator to execute a system command. That's always a bad idea for a web-accessible script, and I don't recommend it, but it would work something like this:
$data = php -q /path/to/your/script.php;
Be very careful with that, especially if you're passing it command line parameters. Adjust the path to your php binary and your script as necessary. This method also requires you to have the CGI version of php installed (this is different than the apache module... see the php manual for details on how to install and set up the CGI version if you don't have it).
Cheers!
Omega Wombat
http://www.drinknation.com