Hi, thanks!!
Guess what... as I was doing screen scaps I finally figured it out!!!!
Since the OP never explained anything, I'll do it for the next person that stops by:
I was trying to get columns with Dynamic Range tags. As the OP reads, this tags are stored as "TXXX/DYNAMIC RAGE" and "TXXX/ALBUM DYNAMIC RANGE".
In order to get this to work, we need to FIRST "Define new tags" in the Preferences Dialog, in the "Tags 1" tab.
And the we head back to Custom tags and select this new created fields:
Now we can adds those as custom columns!
Greetings!