Where are your “modulator” and “carrier” waves coming from? Are you wanting to generate them, or use the track audio for one or both of them?
If you are wanting to track the pitch of an arbitrary sound, then that is very difficult to do, and you may be best to start looking for a VST effect that gives you what you want.
If you are wanting to generate the tones, then your new description is very much like the code that I’ve already given:
(setf carrier (hzosc 440))
(setf mod (hzosc 65))
(mult carrier 0.5 (sum 1 mod))