Hide and show application switcher/dock icon

I have an application that sits in the background and occasionally pops up an image on screen (NSView whose NSWindow is transparent and has a 0-alpha background). I have it set as a UIElement so that it doesn't show up in the dock or the application switcher. But I want it to show up when the user opens the 'preferences' menu item of my status bar icon, which will let them configure it.

I kn开发者_C百科ow this is possible, because iStat Menus does it. But I can't figure out how. How do I do this? Or should I just have it always be present in the dock/app switcher?

edit: Apparently iStat uses one process for the system tray, and one process for preference windows. That's kind of hilarious. I think I might wind up just making it a UIElement and having a hidden preference window that gets sent orderFront when the preferences menu option is selected.