How to publish a 1C web service (IIS or Apache) via VPN?

Question

IIS

Good afternoon!
Such a thing: in 1C, in order for the built-in telephony functions to work, they must be published as a service on the Internet so that the Virtual PBX has access to them. Through the IIS server.
So that an address like "well, only I have a physical server in the office is available from the Internet.
My" 1C integrator "offers to buy a white IP address from the provider and naturally put the screw server on the Internet.
This scares me a little, and I would like to buy a VPS and to connect a VPN tunnel to my computer,
but I don't have enough general knowledge, so how can I configure it to forward the connection to my server when calling the VATS to the VPS server?

Answer 1

My "1C integrator" offers to buy a white IP address from a provider and naturally put a screw server on the Internet.
It scares me a little.

Why expose a server when you can expose a router? And the server will be in a gray network, behind NAT, forward the necessary port to it and that's it.
How can I set it up so that when VATS accesses the VPS server, it forwards the connection to my server?Something like -

iptables -t nat -A PREROUTING -p udp --dst  IP_VPN  --dport PORT -j DNAT --to-destination IP_COMP:PORT
iptables -t nat -A POSTROUTING -p udp --dst IP_COMP  --dport PORT -j SNAT --to-source IP_VPN