i believe...

/click actionbutton#

where # is the number for the action button you want to press. i believe this is a left click, unless otherwise noted.
if you can get a script to press several macros keyed to different action buttons on your action bar, then that's one way to do it.
i've seen something like this mentioned somewhere last year and do not know the exact source, or know how to configure it properly.

good luck.