I want to make a virtual onscreen keyboard using Game Maker Studio.

I want to make a Keyboard program for Windows in which a user can open on their screen, then type, and the keystrokes they press will light up. I know how to do this, but I don't know how to make it work in the background while the user is typing in their browser or on Notepad.exe, any suggestions on how I can make Gm Studio .exe file run in the background without being the active window so other applications can accept the keystrokes, but yet my virtual keyboard that I've created will still light up as I've designed it to do?
Thanks in advance for your solutions.