What do you want it to do? How often will it dial? You can use hyperterminal to setup a connection and use scheduled task to setup a time to connect. Unfortunately you can only do this once a day at the most.

First of all, you must have your username/password stored.

Right click on your broadband connection in "my network connections" and click properties.

Go to options, and uncheck "Prompt for name blah blah blah"

Press OK to save the settings, your connection will dial, you can cancel or connect it doesn't matter.

Now, create a shortcut for this connection to your desktop.

Open Windows Control Panel and then Scheduled Tasks.

Use the New Scheduled Task Wizard from here!

OR

You can use this tool via command line, using at.exe!

AND

If you want to dial this connection on startup, you can drag and drop the shortcut to your startup folder in your Windows Start Menu.

This application dials it on startup:

http://files.filefront.com/VistaStar.../fileinfo.html