How can I set caps lock to a more complex keystroke? In the Keyboard settings, it is possible to set Caps Lock to other modifier keys, but it doesn't allow to put in a custom keystroke.

Is it possible to set it to something like Ctrl + A?

I'm using OS X Lion 10.7.3 if that's of any relevance.
PCKeyboardHack
allows to change the caps lock key behavior. It's mac software, even tough the name may not suggest it :).

(pic from developer's website)