Run Application only on external display


First thing I'd like to say is OSX is one very good OS! Bought a Fujitsu-Siemens 17" LCD display, connected it and without installing a single driver, the OS knew the model of the display I had just connected. :) :)
Now, to my question. Is there any way of customising an application's behaviour such that when my external display is connected, all the windows for that app. open on the external display?
Open the app, move it to the display, then quit. It should reopen on that display. That's the way mine works, but not sure about a PB when you disconnect the display, then connect again.
By default applications open on the main display, but you can make the external the main display from the Displays Prefernce.

From the Arange tab, drag the white menubar to the external display.