[boost] preprocessor question

Hi all, I am trying to find a way to implement something like a preprocessing-time map. As far as I understand, the task is trivial if "keys" contain only one token: #define FIND(x) BOOST_PP_CAT(FIND_, x) #define FIND_key1 val1 #define FIND_key2 val2 #define FIND_key3 val3 And then: FIND(key1) // evaluates to val1 FIND(key2) // evaluates to val2 FIND(key3) // evaluates to val3 However, this approach obviously brakes when keys contain more than one token, like "key 1" (or, to be closer to the real problem, "unsigned int"). So I am wonderring if there is any facility in the preprocessor (or in the Boost.Preprocessor) that would allow me to do this. Thanks in advance, Arkadiy