Panels on NURBS surface in relation to a overlaying diagrid

Hey everyone. 

Im trying to create a panelization on a freeform surface, see attached picture. 

the joints should lay on the grid that was created via the following definition.

now comes the difficult part (in my eyes): since the diagrid that i created has different distances when it flows down the cones, the panel-joints should still be hidden in the shadow line of the diagrid and stay roughly the same size. So they are not affected by the flowing down surface but stay in one size but still follow the grid. That results in the panels sometimes jumping multiple grids before i need a new joint. 

i dont klnow how to put it in a definition. any ideas? i will try to explain clearer if it is not understandable. 

attached the surface, the grid and the definition