Configure VPN in VPN qube to connect tot 127.0.0.1:12345.
Listen for VPN connection in VPN qube:
socat TCP-LISTEN:12345,fork,bind=127.0.0.1 EXEC:"qrexec-client-vm sys-net user.adminvpn"
In sys-net forward connection from qrexec to VPN server 10.1.2.3 and VPN port 12345:
socat STDIO TCP:10.1.2.3:12345
Here is an example:
But it’s using old qrexec format so you need to change it to the new one. Like this for example: