How can I make my own drop down in menu bar

Hi,
I am just getting started with FCKeditor
and i am going to use it so my customer will be able to format an email message

I would like to know if the following is possible

1.Add a drop down box to the menu bar filled
with properties from my data base

[%user%]
[%Administrator%]


2.use those properties and replace them on the server side

for example when the user will format such a message

"This is a message from [%Administrator%]"

the [%Administrator%] will be replaced on the server using my code


Thanks.