Is there a way to call the unrar command via command line and pass the password as a parameter? There should be.
If there is not with winrar, try the 7zip commandlet for powershell, that should definitely be able to do what you want.
Write a quick skript that reads your passwords from a text file into a variable, use a foreach-object loop to iterate over the variable and each time call the unrar command and use the current password.
Not sure if this is elegant, but that’s the first thing that comes to my mind.
Now that you say it, I think I do that too.