Detecting Selection in Noncoding Regions

I am a biology student and do not have much knowledge with computation and statistics. i work on plant intron and have evidence of numerous introns of a gene family undergoing positive selection i was interested in finding if selective constraints are acting on these introns so that it becomes easy for me to predict the modular structure. i downloaded the program evonc but am clueless how to use it since i dont find any executable file on the list of winzip file. could anyone help me on this issue