Based on this SwiftPanda16 reddit post: https://www.reddit.com/r/PleX/comments/5tymws/automatically_create_an_imdb_top_250_movies/, I decided toadapt the script that will automatically generate a new Plex collection using an IMDB list.
Finally i can't do it by myself so i asked for help on freelancer.com and Abdul Wahid M. adapt the original code for me. it is available here
The script will match movies in your existing movies library to the IMDB list, then create a new Plex collection.
As the original one It will also tell you which movies you are missing from your library.
Note: Your existing movie library must be using the "Plex Movie" agent in order for your movies to have IMDB IDs.
WARNING: Use at your own risk! I am not responsible for damages to your Plex server or libraries.
Thanks to SwiftPanda16 for his original work.