Custom drop-down in yui editor toolbar?

Question

Hi all,

I'm working on a CMS where the administrators have the chance to edit all of the mails sent by the system. I'm using the YUI Editor for this. Now the admins can see the content of the e-mails and also the pre-defined values in e-mail like {link}, {first_name}, etc.

Now I'm thinking how could I integrate these pre-defined values into the YUI toolbar. I mean, there'd be there a drop-down where the admin could choose the required field to insert into the content.

Is it possible?