How to connect to a proxy server using a USB modem behind a mobile operator?

Question

linux

There is a USB modem, with a carrier SIM card, which is connected to my computer. The computer has special software that allows you to use it as a proxy server. At the moment, the proxy works only if the devices are on the same network at the internal address 192.168.*.* - well, this is logical, of course.
Question:
Not being on the same network as a computer, how can I connect to it as a proxy from another device?
(since the telecom operator has only a few dozen IPs, it’s impossible to simply set up a proxy outside, as you did with regular wired Internet)
For example, the proxy is located in the city of Magadan. I want to leave Magadan for Moscow and from there enter proxy data - and visit sites through a laptop in Magadan.

Answer 1

No way. Provider NAT will not let you reach the proxy. You can buy a VPS somewhere, raise a VPN and work with a proxy through a VPN.

Answer 2

I think you can block the OpenVPN bundle.
on a machine with a modem client, since it will pass ok for nat,
on a machine from where you need to climb through your proxy server and white IP address.
then by vpn you will get a connection as lan.
Implementation issues remain, for example, a pair of routers with OpenWRT + OpenVPN, in
order to know your current IP on the modem, if there is no static on the end client side of the proxy -
DynDNS.
But the first answer is better.