If you don't have the authority to install PHP's commandline interpreter, and are stuck with it installed as an apache module, then put your script somewhere it can be accessed via the web, and use wget or curl to fetch that web page. Apache will run your PHP script to service the HTTP request.
Also, PHP has a "-q" option for running things on the commandline that supress the default HTTP header output. This is usually just "Content-Type: text/html" and "X-Powered-By: PHP/<version>".
Take care,
Nik
http://www.bigaction.org/