Reading the pyparsing's API I found a function with a suggestive name called replaceWith. Using this function and addParseAction I was able to solve the problem.
The following code is the solution to the problem:
from pyparsing import *
crazyVariable = Empty().addParseAction(replaceWith('comment')) + cStyleComment
print(crazyVariable.parseString('/* foo bar*/' ))
The output:
['comment', '/* foo bar*/']