slartabartfast
It sounds like he wants SONAR to read the notes (and here it is not clear if he means MIDI events or actual audio) recorded and somehow derive the chord spelling and add the appropriate chord symbols to the staff view automatically. Nice trick if you could do it.
Most music notation software that I use can do it, though not to audio, obviously.
I never use it as I am somewhat particular about naming chords, and frequently argue with myself about names, let alone disagree with the software.
So much depends upon context, key etc. that it never does a great job unless the chords are pretty basic.