I did that some time ago with MysqlDumper.
in the cron.php file you need to create, you only need to include the path to the cron execution of the dumper.
call the file "cron1.php" for example and safe it to includes.
then open the msd/msd_cron/crondump.pl and set the absolute path the dumper gave you.
then you should be able to make cron_dumps via the ACP
But this will only work, if you don´t use a password-protected dumper
and, your server allows Perl.
better is, to set the cron in your server cron-settings.
Driving me and my PC crazy, trying to create some pluggins
( IP 2.0 RC-1)