Making a Custom Inventory Item

[ThePaSch]

I think he just wants to "warp" the item into the player's inventory without it physically appearing in the world.

convolution, to do that, you need to create a texture for your item (.tga, Photoshop does that) and place it in your custom story's directory. Then, use void GiveItem(string& asName, string& asType, string& asSubTypeName, string& asImageName, float afAmount);, replacing asImageName with the name of your item image.
I don't think you need the model editor for that, but feel free to correct me.