I actually had not noticed those option at the top but unfortunately what I need is not in the list. The custom "field" I was referencing is actually an additional column added to the Design Steps. What gets emailed now when you selet Design Steps on the email is just the three default columns Step Number, Testing Instructions, and Expected results. We have added Step Name and want to include that in the email as well.
I appreciate your response and I should have probably been clearer on my original post.