The PostEvent command allows a script to post a keydown event with arbitrary modifiers (Option, Command, Shift, Caps Lock or any combination of these). If there is a Tempo macro corresponding to this key combination, then it should run.
PostEvent is called like this for Tempo:
PostEvent modifier,virtual keyCode
For instance, the following call posts an option-w:
PostEvent "O",13
(where the first argument is an upper-case "Oh", not a zero).
A “virtual keyCode” is a keyboard-independent method of identifying a keystroke.