Ok, this approach sounds reasonable!!!
The problem with accessing the model remains.I mean i don't know how to do it.I f you want to spend 5 min to post some code i'll be very gratefull.
You can do it for example with QWidget with QButton, and QDialog that opens when the button is clicked.And when you click in the QDialog button to update Qlabel that belongs to QWidget for instance.
It's the easiest example i can figure out.

Than you in advance