HaloMods "Classic" Read-only Archive

Well opened the .map of bevercreek in SparkEdit, exported it to .obj. Now I used the plugin for GMAX to import .obj... but now how do I get it back to .map so I can jump ingame and see what I did?

I am going to be getting 3ds max 6 soon... how would I get back to .map from there too?

Thanks