casting onmousover

[Lo'oris]

I would like to be able to move the mouse over a character, click a key, and having that spell cast on him without having to left click to target him.

Now, clique does that but only with mouse buttons, that's not what I want.
Click2cast allows to set keyboard keys, but is still missing the point: I do not want to set new keys, I want to use the keys I already have set on bartender! (or whatever bar I am using)

Now, an acceptable addon would be one that targets any raid or party player I pass the mouse over.

The ideal one would of course just allow me to cast the spell on them using the already set bindings.



Now, the questions are:
• is there already an addon who can do that? (I couldn't find it)
if no:
• is this possible? (I can't see a reason why it couldn't)
• does it need to be a modification to bartender, or can it work on its own?