Alpha texture help

[CoasterSim.Fan]

I have a scenery piece that has a pore draw distance. So I wanted to try making an invisible box using alpha textures around it. Not the piece I have right now has a texture applied to it. Now can any one explain to me what to do to have the box be invisible and my object in side still visible? I would like to make all textures with ms. Paint if possible. Any help would be appreciated.

[Vodhin]

My understanding of alpha textures is that you need to images:

The image:
http://www.vodhin.net/CustomScenery/Vodhin/Electrical/8Bit_Small_Insulator.JPG

and the mask:
http://www.vodhin.net/CustomScenery/Vodhin/Electrical/8Bit_Small_Insulator_Alpha.JPG

In your 3D editing program, you'l only use the Main Image. In the importer, you'll add both textures when creating the OVL, then assing them to the mesh that uses them, using the SIAlpha or SIAlphaUnlit type.

You should first try a simple wall, with some kind of image. A Red box, perhaps (don't use blank- I'll get to that later). The mask should be black with a white cut out where the image goes, and RCT3 will not drawanthing from the Main Image where the Black is in the Mask- that's why you avoid black in the Main Image- it screws up the alpha. Use a very dark gray if needed.

So, to make your wall invisible, you could just have an all black mask, in theory- I haven't tried it yet...