I have an ice cave!! Yeep. It's a great pack, and there is a lot of ice stuff in it.
http://nowethekid.deviantart.com/art/WOW-Pack-2-365777421 (http://nowethekid.deviantart.com/art/WOW-Pack-2-365777421)
Download it, and there is a GIANT ice cave in there. ;)
Oh, it's simple. Enter the material name.. it's not simple for newbies in the mesh-making thingy, but here's how.
Go to the Object Maker tab, and then switch to the second tab. Enter the meshes name, and like you said, it is BaseWhite. Change 'BaseWhite' to 'AC3D/IceCave/Mat015_Tex142'.