Here is a little program to add the possibility for Steam users to join server by clicking links (like on this page (http://stats.mx-bikes.com/servers.php)).
Run the program and locate your MX Bikes executable :
A .reg file will be generated on your desktop. Click it and accept. It's done :) now you can use links.
Steam users will see the following popup to accept :
DOWNLOAD LINK (http://www.mediafire.com/file/xdadk7746hal7zu/MXB_Link_Me.exe/file)