To set up the mode switches its pretty straight forward once you have your head around it, but it will involve remapping some of the controls in the game to a key, then mapping that key to the button on the controller. There are a couple of gotchas, but a search will find you the solutions to those (clutch button setting and shift key). The trick to it is to stick with the standard bindings to start with (just choose it from the drop down in the controller options) and play around.
I have just set up the mode switches to have a few of the buttons do different things when you flick it.
