effect idea: feedbacker (like boss df-2)

[Mighty Pea]

Does this allready exist?
The idea is that it reproduces the note that's playing when you press down on the pedal (or hold down a midi-key of choice, in this case, obviously) as something feedback-like. It often sounds nothing like feedback, but i like the things it does, and would like to have this in vst form. i've found two feedback plugins, but they don't take input, and just create pitched feedback.

any suggestions?