Windows service with balloon tooltip

OK After some serious research i've managed to display some balloon tooltips on a notifiyicon, hooked up to a windows form. But i inteded to write a windows service instead of a form-based application. Since you need a window handle to run the shell_notifyicon function, needed to display the balloon tooltips, and i don't seem to find the handle from a service, i have a problem :-( Does anybody know how to get the handle from a windows service, or any way to hook up a balloon tooltip to the notifyicon from a service?? Thx in front Jochen