An external Windows program or app can be launched from a button in the Snap Core First app.
Here are the steps:
1. Select the Settings button at the upper right of the screen.
2. Select the button that you want to use to open the other program/app.
3. Scroll down and select the Add Action button.
4. Find the Launch Application action, and select it. You will then be offered several standard choices, depending on your hardware and what apps and programs are available on your device:
You can choose one of these applications, or you can choose "Browse for application or file". This will open the File Explorer, so you can choose what to launch.