Once created/added to my 'Studies', it is not available to select as a column. I notice that none of my custom scripts are available to me in the list of studies.I have the following on several timeframes in my Watchlist.
Edit: I figured this one out. For others benefit...you need to add the script code via Custom Quotes/Custom 1, etc.
From the Menu in my Watchlist, I do not have the option to save the watchlist as a scan. There's only an option to 'Create scan query'.To get the scan to run automatically (every 3 minutes approx) save the watchlist as a scan, found in menu on upper right.
Further info is in the Education Tab in ThinkorSwim.