lulzfish
Pandora Defense Squad
There should definitely be one analog controlling the mouse, but I would use the other analog for scrolling and then either the shoulders or the left and right of one of the digital pads for clicking.
Edit: Using the dpads would be slightly easier since you would have left, middle, and right already, whereas the shoulders would need to be pressed simultaneously to simulate a middle-click.
Edit: Using the dpads would be slightly easier since you would have left, middle, and right already, whereas the shoulders would need to be pressed simultaneously to simulate a middle-click.