Logon Studio fill function

Hi, I've been using logon studio with windows7 for awhile now and it's great, but I have one small issue with it.. You see, I use a laptop with 16:9 ratio but I use an external monitor that's 16:10 because that's how I like it. However, if I use a wallpaper that's 16:10, it would look great if use the monitor but if I detach and just use the laptop, the login screen wallpaper would get stretched. What can I do about this? Is there any way to make it use the fill function like the background?