Merge different patches
 

Hi all,
I have built my case using snappyHexMesh. My geometry consists of many "obstacles" in a rectangular domain. The case is 2D so i have followed the wingMotion tutorial to get a 2D mesh using an stl surface (from gmsh) and snappyHexMesh+extrudeMesh+autoPatch.
My problem is autoPatch. Basically what i need is the same patch (wall) for all the obstacles, but autoPatch creates a lot of patches auto1,auto2,auto3... (the number depends on the shape of the obstacles and on the angle used with autoPatch). How can i get only 1 patch for all the obstacles? Is there a toll, for example, to merge different patches? Or does anyone have an idea how to solve the problem, without correcting the boundary dictionary?

thanks

andrea