Command for Cron-task below the docroot

Hi,

i need to run a cron-task, which is below the docroot. How can i submit a task? The following failed:

##Submit Task##
/usr/bin/php -q /var/www/vhosts/mydomain.de/crons/cron.php
php -q /var/www/vhosts/mydomain.de/crons/cron.php

##Submit PHP-Skript##
Path: crons/cron.php Order: -q
Path: crons/cron.php Order: php -q


Thanks a lot for help in advance.