Create a "Splash.jpg" or whatever you want to call it. Then save the below text as "Loader.skin".
If you change the name of your splash image, you will need to change the name in the 3rd line of the skin file.
MEDIACAR F-CNS(800X600Stretched)Menu Skin
/, L, x, y, w, h, color R;RGB, G, B, font size;FONT, font name, Code;LABELCODES, Tooltip;LABELALIGNMENT
Then place both files in your skin directory.