Assign IPs in the same subnet

This is possibly a silly question. I am not an expert in networks and lack the proper lingo to explain my problem.
I am using tailscale to connect my laptop to my home office when I am on the move. There is a particular (windows only) software that I use that is very old. I have license for it. Any machine on the LAN automatically gets assigned a license as well. My problem is that when I connect to the server at home through my laptop, I get IP assigned in different subnet (?) - e.g. server is 10.190.x.x, my laptop is 10.100.x.x. Therefore, when I start accounting software on my laptop, it is not able to discover license server running on my home server (10.190.x.x). How can I assign the IPs for all my machines in same subnet?

That is a license server like flexlm? It most likely works via IP broadcast, which means your laptop sends a packet which every device on the LAN receives including the license server. The license server sends back a response.

Unfortunately IP broadcasts don’t traverse the VPN network, there can be too many broadcasts for that to work well. The license model where all devices on a subnet won’t work remotely.

flexlm and similar systems often include a configured mode, where you enter in your laptop the IP address of the license server. That might be described as a Corporate or Enterprise mode, where there is just one license server which handles an entire campus or large building. If there is a way to enter an IP address of the license server, you can enter the 100.x.y.z address of the Tailscale interface on the license server and access it remotely. You’d need to install Tailscale on the server running the license manager.

Thank you very much. I am not very familiar with flexlm or how it works. This software can run as server or client. Client looks for a service started on port 9999 on the LAN.
This software allows setting proxy settings. Can that be of any use?

I don’t immediately know what a proxy might do here.

You’d need a way to specify an IP address for the server, not have it broadcast trying to find one on the LAN.