Trouble with reporting on custom fields and creating clickable URLs

I'm trying to filter a query by a custom field but that custom field does not appear while other custom fields do.  Is there something I need to do to change that field to make it appear? I didn't see a difference between the ones that appear and the one that doesn't appear.  The other issue that I'm trying to figure out is that on one report I have the ticket ID but it's just the ID and not a clickable link to the ticket itself.  Is that possible?  Thank you!