Would it be possible to switch "alt" and "space" ingame while <not> typing?

I basically would like to have "alt" bound to the "space key" during combat, so instead of "alt+1" for a skill I would now be able to do it with "space+1".

If you are wondering why, I'm just having an issue with my left thump finger atm and it would be great if I could keep it stretched at all times (hence using space instead of alt)

Shift and control arent an option either cause I just cannot do it with my pinky finger without losing track of movement keys >.< I use "Alt + combination" for everything basically ^^

If anyone knows a program that could do this for me, that would be great! ^^