How to connect to MSSQL through VPN?

Question

VPN

A little chaotic, but in short:
What is: there is a server under windows 2008R2, MSSQL is running, a VPN is configured to access the server from the outside, also, users log in via RDP and use programs on the server. Including the Loan Officer program, which uses a database in mssql.
What you need: but it is necessary that users who have access to the Internet via USB modems can, by connecting via VPN, connect the Loan Officer directly to the mssql server, because. rdp over mobile internet is very, very slow.

Now, when launching the Loan Officer, I specify the ip-address of the server to it, but it cannot connect to it.
Please tell me how to fix?

Answer 1

Does the server even listen to the TAP interface port? Or is it only set on localhost?

Answer 2

and set up an rdp connection to turn off wallpaper, composites, forwarding of the flyer / printers and the use of 16-bit graphics on the server side by politicians?