Hi Steve and others, Hope this is helpful for any custom work that you do in the future. This will be an intermediate level summary that is designed to place custom muntins in Core catalogue doors that have windows but do not allow automatic lights in the DBX or cad blocked "Custom Muntins" with this tool, . Open new plan and place a short section of wall in your floor plan. Place a door from the Core Catalogue, convert wall type to "Room Divider". Open door DBX and remove Casing