actually thinking about how I could use a button on mouse (middle mouse on my current one, or side buttons on some others) as a key to shift left side of keyboa

actually thinking about how I could use a button on mouse (middle mouse on my current one, or side buttons on some others) as a key to shift left side of keyboard to right side. That's really all I want. A way to have hand on mouse and still be able to type (though I avoid using mouse). Should be doable with autohotkey