http://msdn.microsoft.com/visualc/vctoolkit2003/

copy nmake.exe from .net SDK into bin directory

use the shortcut to start a cmd box with the environment variables set

Blog about it
http://blogs.msdn.com/brianjo/archive/2004/04/17/115335.aspx

Manual from Microsoft about nmake.exe

review from a linux point of view:
llg.cubic.org

If you have a Visual C++ 6 IDE, just copy over the bin, lib, and include directory, and compiling works. Debugging does not.