Multiple keyboard settings for one action?

[maradyne]

Is it possible to set more than one acceptable key for an action? For instance, setting both F and one of my mouse's side buttons as possible choices to 'Attack'.
Even better if it would be possible to set a single button to initiate a Force Attack (rather than toggling the mode) in addition to the normal simultaneous button press style, but I know that's a stretch.

A mod that accomplishes the same thing would also be fine. I took a look through the workshop, but didn't come up with anything suitable.