[pluggo] making a drop down with pp

Hey there,
does anybody know if it's possible to make a drop-down menu with the pp-object and a 'choices' argument?
I use for example: 'pp 1 waveform 0 2 choices saw triangle square' as an object, but I get an x-slider (in my plug-in) on which I can choose, but I would like to have a drop-down on which I can choose if it's a saw, triangle or square.

Is that possible? And if it is, how?

Thanx guys for your help

Have a great day
Peer