Who I have the same questioned this topic

First, a little background. I have a computer, Samsung Galaxy Book, with both a cellular modem and wifi. I use wifi to connect to a lan that also has an connection to the internet. The computer is running Windows 10. When wifi is off the cellular modem connects to the internet. When wifi is on, the lan internet connection is used. I have an unusual situation where the cost of using the lan internet connection is greater than the cost of using the cellular modem connection.

My question is: How can I set up my computer to force the cellular connection to have priority over the wifi connection thereby using wifi to only connect to local devices and the modem to connect to the internet? In other words, I want the internet gateway to be the modem's IP address.

Thanks for any help.