That's it, thomasabarnes! Thank you so very much for your help!! I tried so many combinations, but for some reason that option elluded me! I really appreciate your help! You made my day (or evening)!!
Let me just confirm something real quickly, if you don't mind.
I put a microphone in mic/line 3 of my steinberg. When I click the "left" option (see image), the microphone records on both meters of the channel, like this:
If I click on stereo, it records on the left meter of the channel; like this:
It seems like each microphone input for steinberg is one side of a stereo line (every two microphone entrances is a pair). Does that seem about right? (I apologize for not expressing myself correctly - I still lack the vocabulary - but, hopefully, the pictures will demonstrate what I mean.)
Thank you again for your great help!