How can I change the keys?

[Cesar_BCN]

Hello

I'm trying to change the first keys row functionality. I want to press
a key (for instance: the '8' key) and emacs writte the symbol that
result of typing Shift+key  (for instance: the '(' symbol ).

But I want to be able to writte numbers with the numeric keyboard.

To the moment I have not esitate so when I change the key '8' (for
instance) the other '8' key (from the numeric keyboard) is changed
too.

Does someone of you have the answer?

Thanks so much.

César BCN
cesarTMP (AT) gmail (DOT) com