First suggestion? Unless you've got witnesses to an oral agreement giving you an exemption, and if there is some sort of intellectual property agreement you've signed or implicitly accepted as a condition of employment, you're going to need a very good lawyer. The company is likely to have deeper pockets, and most of the high cards. Even if you're absolutely right, they can tie you up in court until your grandchildren die of old age.
Corporations don't have morals; they have interests, and your best chance of winning this argument is to show that it's in the corporation's best interest to leave the subject modules on CPAN. Right and wrong don't really come into the issue.
Information about American English usage here and here. Floating point issues? Please read this before posting. — emc