No solution from me, but maybe a way around the problem.
You don’t say what you need, or in what way it’s not rppropriate. But if you think that sphere mapping is, how to say, not powerfull enough, then maybe you can look in to the cube enironment mapping extension. This one is a very acurate reflection method, if it’s what you need, I really recomend using it (if it’s available of course).
Or maybe you can do the maths yourself. You said you found the formula in the MSVC6 Docs, and I have seen it myself. It’s not too complex, so why not try to do it yourself? This, on the other hand, requires that you do have the modelview matrix somewhere. Either get it directly from OpenGL, or use your own transformation code, that holds a matrix for you, and when doing transformatins, you transform your own matrix aswell as sending the transformation to OpenGL.