Ok, obviously this was still too difficult. Let's go over this step by step.

The first link is a link to the 1.23 patch. It will upgrade your JJ2 from version 1.20 to 1.23. Run the file, and when done correctly, you will see "1.23" in the bottom left corner of the JJ2 menu when you start JJ2.

Now download the second file Newspaz linked to. This is the serverlist patch. If you live in Europe, run "europe.reg". If you live in America, run "america.reg". If you live somewhere else, just use whatever's closest to you.

Once you've done all that, you should be able to play online.