pathfinding in geomipterrain

Hi!!
I add in my scene a geomipterrain. It is created by PNG image. There’s a lot of mesh on the surface generated by geomipterrain. I’d like to move an object on the surface as in a rts game. To do this, i see pandai in particular the pathfinding section. I understand that i use initPathFind to set the navigator mesh. I’d like that the navigator mesh is the surface generated by geomipterrain.
is it possible? How?

Thank a lot!!!