"Open With" Questions

I have created a dashboard over a query over NonConf. My users would like to use "Open With" over the TranID field, however "Open With" is not an option when you right click. It is my belief that the field (tranid) must be a key to the table (NonConf) for "Open With" to work. I believe this is the case but am not sure how to see the keys for NonConf. I looked at Data Dictionary Viewer, but could not interrupt the indexes. Can anyone point me in the right direction to understanding how "Open With" works and why it does not work for TranId in NonConf.