"Then, I need to create a backing track for the solo, but I don't know the chord progression.

Where do I find the "Chord Chart" that contains the chord progression information?

Why don't you go to the folder I mentioned, pick any wma file in that folder, and try it with your method, and see if you can extract the chord info for that entire track."


That method will give you the chords it's played over
\bb\RealTracks\Guitar, Acoustic, Soloist PopBalladBrent Ev 065\ag5071.wav
you will end up with a file that has all the chords displayed in it as cue points
you can then create your own solo to be played over a progression by coping sections from that source track.
You also have Extensions > Region Playlist that is a quick way to arrange sections and play smoothly from one section to another.