Years ago ppjoy would have been suggested. You can still find it, but its not really in development anymore. You may consider reading about autohotkey, but I don't know if that is what it is used for.
There are arcade style USB trackballs available. Looking at your bartop, I don't think that will be an option.
Alternatively, you could do like I do. When I need to use a mouse on my arcade. I do. But it ruins the experience and there is really no room.
You have more free surface area on your CP than I do on my CP. You should use a small wireless mouse if you attempt this. Another option is one of those gryation presentation mice. I had one that I was convinced I was going to stuff into an arcade style gun. I could point it like a gun though. *shrug*
Similarly I have Sins of a Solar Empire, which I don't play because of its dependence on a mouse and my best PC is in my mame cabinet.
Lastly, you could try a touchscreen.