No, with cron, you put the command right in. If you have CLI enabled, even better. One of my typical cron commands looks like this:
####################################
# min # hour # mday # month # wday #
30 1 * * 1 /usr/local/bin/php /var/cron/test.php
This is saying at 1:30AM on every Monday, run test.php
You give the full path to the php binary, space, full path to the php script. This only works with CLI enabled. Otherwise, instead of pointing to the binary, you point to lynx. You can also specify the binary in the php file with a shebang, like this
#!/usr/local/bin/php
<?php
echo "Hello";
?>
Then, in the crontab, you could just point to the file.
####################################
# min # hour # mday # month # wday #
30 1 * * 1 /var/cron/test.php
HTH
