An idea if possible for replacing blank sections of audio clip

I do voiceover/audiobook producing. One of the more time consuming parts of editing/mastering is removing all the little clicks and noises between spoken bits that aren’t removed with declick and other plugins.

How difficult would it be to create a plugin similar to truncate silence, but instead of truncating, replace those bits with clipboard content. In this case it would be a small clean section of the clip.
I can use a noise gate, but that destroys the noise floor and can be destructive. I wish I could find a noisegate that allowed upper and lower db limits so it would only remove sound within a certain range instead of everything below a certain db.

How hard would that be be to modify the truncate plugin?