I am adding picture moulding beneath my chair rail in the dining room. I have run into a problem I don't know what to do about. I have one 50" space that has a 30" cold air return almost in the exact middle. I want to do 2 panels (17.5 " wide each) with 5 inches between and each end as this is what is working out perfectly for all other spaces. What do I do when I come to the top of the air return? Any suggestions? Any pictures of what this will look like? Please help if you can. I am a novice at doing this. Thank you