tilesets problem

hello guys/girls

here is my problem

I would like to create walls around my tiled path

the method I find is to create a wall in the 8 directions around each path tile. but I can't find a way to delete or not create the walls tiles whose overlaps the path.

this makes a problem when I activate collisions on the walls tiles and my player is

repelled from the area

here's the caps

dl.dropboxusercontent.com/u/164432510/test.capx