How to send part of requests through VPN?

Question

linux

VPNC system, hardware and software must be used: Centos 7, NGINX, ASP.NET CORE.
Can you explain the essence of how this is done?
Task: there is an ASP.NET Core application site available to everyone on the network, but some of the packets need to be sent to the server via VPN using VPNC. What is the best way to do this, do I need to configure NGINX?

Answer 1

(subject to clarification in the comments)
This is completely independent of the use of NGINX, ASP.NET, etc.
1. raise VPNC (google instructions);
2. register a route to the server (where the data is located) through the configured VPN.
How would everything.
The original question is incorrectly worded. Not part of the packets\requests via VPN, but access to a specific server via VPN. The task is typical and simple, but the cisco VPN is wild exotic.

Answer 2

It doesn't matter which VPN. If the target address is reachable through the VPN, the requests will go through the VPN.