How do I share Kindle Books with highlights and notes between say "paper White" and "PC Kindle App"

I am horribly frustrated because one would think I could copy a *.azw   format file from one folder to the other and obtain all the highlights made but it seems that does not work.
There is some service called, "Good Reads" but a book recommendation service is not what I am looking for
I simply want to go out with my-E Reader Paper White and the book contained and mark it up whether it be a .pdf or azw  file
and copy it back to my "PC Kindle App"  and get all the highlights, bookmarks and notes?

Any one solve this one yet?  No Amazon is clueless about being able to do this - Help would be appreciated as I do not relish
updating highlights and notes twice for no good reason!!!!

Best solution wins!!!