Connecting a USB button device

[ndogata]

I recently bought a "Stress Button" from London Drugs which is a simple button connected to USB.
I would like to use this device for a software gameshow program called Questionable. In Questionable, we can select which key on the keyboard acts as the players button.
I would like to know how to rig it (write a macro?) so that when the button is pressed, it acts like a key on the keyboard is pressed.