It's much like you would do with cpanel except it isn't the brand "Cpanel" so I assume it is the server directly.
First of all, it tells me to make sure it is all in www/ and the information entrance area has a www/ and then you type your cron job, if that means anything.
Secondly, my forum's Server Settings area says my SMF directory is /mnt/w0514/d43/s47/b01da51d/www/bmsprint/death/forum, so since I have to start with www I used bmsprint/death/forum/ (and then whatever you add in the files.) Does that help at all?