Okay, let me see if I can walk you through setting up a Cron Job if you have never done it before.
First, take that code, and save it to a file, and that can go anywhere, in your root home directory, in the public_html, wherever. Call it whatever you would like to call it, as the name doesn't matter.
Next, go to your control panel (The CPanel, not in MovableType) and click on Cron Jobs. From there, select standard.
You will select the minute you want to run it (Typically I do it on 00) then the hour (Usually for me, that's run at 0) then the days you want to run it (Every day typically for me at least) Then every month, and every weekday. Basically that would run the script at Midnight of every day.
Then, for the commandline, you would want to use 'perl <path to directory>' and also enter an email address to get notifications, in case something goes wrong.
Now, to find out what database, and password you used, go into the directory you put MovableType in, and open up the config.cfg (I think that's what it's called, the file you edit at the beginning to set up the databases) and there you can get the database. And, then open up the file mt-dbpassword.cgi (Again, I believe that's the name of the file) the one that you used when you setup the password, and there's your password.
As always, if you need any help, or more of a walkthrough, PM me...