Change and customize Windows 7 Logon Screen Wallpaper Script

Hello To All the Scripting Gurus',

I know this can be done, but I've only found that this can be done manually. I'm looking for a batch file or script that will change and customize the Windows 7 Logon screen wallpaper. I have an image for it. I'm just looking for the batch file or scrpt to do it, so I can use the batch file or a script to use in Configuration Manager 2012 and push out to all 800 production machines.

Thanks,

J