Modding proficiencies

Hey everyone I would like to create a mod that changes the proficiencies in a way that when a character spend stars on a certain proficiency he will get a general ac bonus, and on another he gets thac0 bonus, or thieving skill bonus, not related to certain weapon, so that way I remove all classes but one and leave only proficiencies. I guess this mod will involve the file wspecial.2da or stylbonu.2da, but I really have no other clue than that. Thanks for any help and any good intention