How to implement simultaneous operation in networks with coinciding ranges?

Question

Computer networks

Available:
1.computer based on windows xp with an accounting program configured to connect to a database on a corporate network with an address that falls within the range of the Internet (computer address on the same subnet as the database server). The computer address is configured manually, 170.xy220, the main gateway is 170.xy1 The
local address of the adapter for the Internet is configured automatically via DHCP from a local router.
2.equipment for connecting to the Internet and corporate network (twisted pair).
Task:
it is necessary to ensure correct simultaneous operation with these networks.
The problem is that when connected to the Internet, the accounting program cannot contact the database server.
I will consider any options, preferably with minimal setup time.

Answer 1

And what serves as the gateway for the server and the Internet? what IP?
In any case, make two routes - one 0/0 to the Internet, the other IP/32 through another gateway (or interface?). The console command route will help you

Answer 2

Why did you choose 170.xxx ? Read what addresses CAN be used in LAN so that there are no such conflicts and reconfigure the network:
https://ru.wikipedia.org/wiki/%D0%A7%D0%B0%D1%81%D...