In the attached report I'd like to create additional columns based on a date filter. I’ve highlighted the cells where I want the columns (S7, AB7 etc) added for each month between 1/1/18 – 2/28/18. There are other columns where I don’t want them to change but to be what is already there (column N – R, W-AA, etc.). The current formula I'm using doesn’t seem to be cooperating and I don’t know if it’s due to the order in which I’ve put things. Any guidance would be greatly appreciated.

I tried attaching the report but couldn't find the option so hopefully this screenshot will show how I've entered the function.