How to undefine a function / enum

[megreen]

Does anyone know how to 'undefine' a function and/or enumeration ? I am including two DDK header files, both have duplicate macros, enums, and functions. To get rid of enums I can do #undef, but what about enum and functions? (BTW, I can't change the include files because they have to be built on many different environments with the DDK. (Microsoft !!)
Thanks for any help