Changing Value for Float/Int Box Without The Mouse?

Hi I am in the process of building an arduinome and one of my hopes is to design various GUIs that I could navigate simply using the keyboard and arduinome buttons, no mouse. I was wondering if it's possible to use MIDI or keyboard information to select different number boxes which I could then just type numbers into. So essentially, instead of clicking on a given number box, I could press a button or press a key in order to select that number box. How might I do this?

Thanks!