How to use enum values in a rand() function

How can I use a rand function that generates a random enumerated variable? This is what I so far have (it's spitting out garbage numbers):

enum pieces { FLAG = 'F', BOMB = 'B', MARSHAL = '1', GENERAL = '2', COLONEL = 
              '3', MAJOR = '4', CAPTAIN = '5', LIEUTENANT = '6', SERGEANT = 
              '7', MINER = '8', SPY = 'S' };

int gamePieces[12] = { FLAG, BOMB, MARSHAL, GENERAL, COLONEL, MAJOR, 
                       CAPTAIN, LIEUTENANT, SEGEANT, MINOR, SPY };

int rand_piece = (rand()& gamePieces[12];