You are confusing copying a class with subclassing. What you have done is to subclass a primary class. You can copy a class from one class library to another (see the help for specifics on how to accomplish this). Any changes you make to the copy of the class (in the destination class library) will have no effect on the original class (in the original class library).
Hope this helps.

>I made a new class, based on a primary class to be able to modify the code and to adapt it to my necessities (without affecting to the primary class), but when I try to modify the code I see that I don't have neither a single line.( I saw the code in the primary class ) How do I to get the code of the primary class?
>Can I do that ?
>
>Thanks.