The local computer (comp 1) is connected to a remote computer (comp 2) with Remote Desktop. On the remote computer (comp 2), I try to establish an VPN connection to a different remote computer (comp 3). Once I try to establish the VPN connection from the remote computer (comp 2) to the second remote computer (comp 3), Remote Desktop freezes on comp 1. It is not possible to connect to comp 2 again via Remote Desktop.

What can be done to connect to this remote computer (comp 2) after it establishes a VPN connection?

The only thing that comes to my mind is to install a second NIC and configure Remote Desktop to accept connection from this NIC while VPN is working from the other...

What do you suggest?

EDIT:

I want to use the internet connection of the VPN, so all traffic should go over the VPN but still RDP working.

My IP: 100.0.0.1
The IP where I'm connecting via RDP: 200.0.0.20 (Mask: 255.255.255.192, Gateway: 200.0.0.193)
Where the 200.0.0.1 connects to VPN the IP of the VPN is: 65.254.61.250

Will routing like this help (Command is issued in 200.0.0.20, the RDP location):
route ADD 65.254.61.250 MASK 255.255.255.192 200.0.0.193

Couldn't add gives the error: The route addition failed: The parameter is incorrect.
I tried before connecting to VPN.