Attached is some map loading code with a custom tile set. The trick is you want to export the layers and load those, not the map file itself. You export the layers with the sc save button on the top middle of the map editor screen. Think of layers like layers in photoshop. You can have transparent parts that let the background show through. If you only care about one layer, you can load only one.
If you download my samples project there is map loading in some of the programs. Look at slimebump2 for a 64x64 4 way scrolling map with custom background tiles I made in smile tool. Note I have the original map file and the exported layers in the folder. I have another, I think it is just called mapload which is basically the code I posted previosly. Hope that helps.
Can someone make me an example and send it to me. Could you try to make it as simple as possible. All I need is to figure this out and then my game will be able to become more than a simple comic strip.