Create a cron job to execute a php script using php

[dfutura]

I need to create a cron job or something similar with a php script. I try to create a file usingh php in etc/crontab like this:

$archivo = '/var/cron.d/pruebaCronMandaMail';
$fp = fopen($archivo, "a");
$string = "/usr/bin/php -q /var/www/vhosts/domain.com/httpdocs/createCronScript.php";
$write = fputs($fp, $string);
print_r($write);
fclose($fp);

But with apache user i cant create this file.

How can i do?