A front end component and a technique are provided. The front end component allows a transformation rule writer to specify syntax structure of interest, as well as what action to take when a syntax structure of interest is found. Example syntax structures include function call, variable declaration, math expression, etc. Typical actions include matching, replacement, or copying. The technique allows transformation tool writers to translate the specification into actual query and manipulation commands on the program representation. It is structured to be target language agnostic and, therefore, can be easily re-targeted to different programming languages.