Is it possible to make external numpad or second keyboard only input to a certain window?

I picked up a external Logitech numpad recently and figured it might be useful to use it for macros.

However, since it's a numpad, every time I will press the button to set off the macro, that number will show up in whatever I'm typing, thus forcing me to backspace.

Is there a way that I can make the input from this numpad be redirected so that only one window actually receives the keystroke?