Depends on which variant of windows you're using but for XP you can enable an x-Mouse type of behavior through a MS (official) addon called TweakUI. What this changes is that when your cursor moves over a window that window immediately comes to foreground (you can change the speed too, I use it with a 250ms delay) so that you only need to move the cursor over the screen. That all said I don't see how this would be an isse as I think its technically possible (the bar changing anyway) with the built in macros. It might be a two button press though not sure.