

Since the track is very long I don't want to do it manually with copy and paste.

Or you can save channel presets, mixer/instrument/effect presets, scores, automation-clips individually, just the ones you want to copy. The Chord Stamp feature in FL Studio can be an incredibly helpful creative tool to assist in coming up with chord progressions, even if you don't have much kn. If you don't have sound samples available, you can download them from FL Studio's developers' website.
