[Libreoffice-ux-advise] Need advise of our wonderful UX people

Hello, trying to add a possibility to add a random attachments when a
document is sent as mailmerge by e-mail.

The existing dialogue is

http://people.freedesktop.org/~fridrich/mailmerge.png

I would love to add a way to fire file-picker to chose attachments.
Considering to put a button aligned vertically with the "Copy to..."
button that would fire a file-picker.

Now, I am not sure whether it is the right thing to do. I guess a user
would need to have somehow a feedback to see which documents are set to
be attached. What would be the best way to do it.

Please, add me to the answers explicitely, since I am not subscribed to
this list :(

Cheers

Fridrich