I see, so I can develop an addin template of some sort and apply the
template in exchange???

Perhaps if I explain the need, that would make things easier ... I
appreciate all your feedback.

I have developed an Outlook 2003 add in that places an extra button on
the standard tool bar .. the add in displays the list of all Query
Based Distribution Lists available and accesses active directory to
dynamically display the members of the DL.

Having the button the the standard toolbar is not the most ideal
location as most users will be using the contacts listing dialog box to
select the DL they would like to email. Being able to customize
(programatically) either of the two dialog boxes explained above to
include either a button or custom control to display the members of
Query based distribution LIsts is what I am trying to achieve.

A Million thanks to your replies.
Sd