How to navigate through toolbar buttons by using arrow keys?

[don_AC64]

I have created a simple toolbar, that is, in fact, a virtual keyboard, so that, when I invoke it, I can insert any character by clicking the proper button. I use it when I write long documents and I need quickly a special character.
But it would be better to use it without having to take off an hand from the material keyboard and to click on it with the mouse.
So, I need a way for navigating through the buttons of the virtual keyboard by using the arrow keys of the material keyboard and execute one of them by pressing Enter on the material keyboard.