Add to default link code (FCK)

Hey all.
I want to add this code to the link button.

class="links"

To explain more when you click a link now it turns my text to...

<a href="h**p://www.link_here">link here</a>

I want this to be the code when it's clicked...

<a href="h**p://www.link_here" class="links">link here</a>

Thank you for your time.