Dynamic SSH tunnel: How?

Hi. I want to dynamically use an SSH tunnel to connect to different (RDP) hosts behind that tunnel.

What I'm doing now:
Create SSH tunnels for every RDP host like this:

ssh tunnel 1
Host: 10.10.10.10
Source: 127.0.0.1:10020
Destination: 192.168.1.10:3389

RDP 1
Host: 127.0.0.1:10020
Set "ssh tunnel 1" as VPN

Now I tried a lot with nesting and googled, but I somehow can't figure out how do this dynamically. I get to the point where the ssh tunnel creates sessions with dynamic ports, but I can't seem to get the target RDP IP in there.

Goal is to only have one dynamic ssh tunnel and several RDP entries that use this tunnel with dynamic allocated ports. Any help appreciated. :)