PHP exec() as Background Process (Windows Wampserver Environment)

I'm trying to setup a php trigger file that will set off a background process. (see this question)

I'm doing this on a Windows Wampserver environment.

So for example I have trigger.php that runs the exec function that calls for my backgroundProcess.php to be parsed and executed.

However the problem is that my trigger.php file is waiting for the exec() command to finish running backgroundProcess.php before it stops. The background process runs for about 20-30 seconds, and trigger.php is waiting all that time until backgroundProcess.php has fully finished.

Is that making sense? Here is the trigger.php file that runs the exec() command

exec('C:\wamp\bin\php\php'.phpversion().'\php.exe -f C:\path\to\backgroundProcess.php > C:\wamp\bin\php\php'.phpversion().'\dev\null &');

Basically, I'm wanting trigger.php to just trigger off the backgroundProcess and not wait around for it to finish.

EDIT

Problem solved with the following command:

$WshShell = new COM("WScript.Shell");
$oExec = $WshShell->Run("C:\wamp\bin\php\phpVERSIONNUMBER\php-win.exe -f C:/wamp/www/path/to/backgroundProcess.php", 0, false);