c++ keyboard hook

I'm writing a program that uses a keyboard hook. Currently the way it works is that when the hook is installed the user can open up notepad or any app, type in there and the hook will record all the keystrokes; however I need the hook to intercept the inputs and not let other applications take control of the keyboard. So if I open notepad and press a key the hook should record it but the key shouldn't appear in notepad. Does anyone know how to do this?