Hook when hovering on a menu item in Eclipse

I'm trying to display a message in Eclipse global status bar when hovering on a menu item.

I had the part to display the message (but I'm pretty sure it's the ugliest way I could have found):

if (window instanceof ApplicationWindow) {
    ApplicationWindow appWindow = (ApplicationWindow)window;
    appWindow.setStatus(message);
}

But I can't find how to run that code when hovering on a menu item. I've got the complete control on the menu and its items creation but I don't see where I can plug my code so that it is executed when hovering on a item of my menu.

The reason I need that code is that I'd like to display a description of a Eclipse Monkey script when hovering on a menu item in the Monkey menu (see bug #132601 for a description of this enhancement).

If anyone has an idea, I'd appreciate.