You may choose to click "Auto connect" if you want this tunnel set up every time you start up windows.
VITAL: be SURE to click SAVE after every edit - if you just click CLOSE, it treats that as "delete this tunnel" - ouch!
Once you hit SAVE on the settings, you can activate the tunnel
by double-clicking on its icon.
The icon changes to show a yellow lock when it is working (a lock since SSH is encrypted.)
Now, instead of asking to connect to the distant machine's IP address, you ask to connect to "localhost" or IP 127.0.0.1.
For Remote Desktop, connect to 127.0.0.1:3389 or if that gives an error message, try 127.0.0.2:3389 instead.
SSH Tunnel Client lets you have multiple tunnels open at once if needed. It can minimize into the system tray to limit screen clutter, and you can select the preference option to start SSH Tunnel Cient when windows starts up so it is always ready.