when you right click on any icon in windows, you will find some menus there.
you can add your custom menu here by following:-
1. open "regedit" from cmd
2. goto hkey_class_root
3. select file type, you can select * or you can select any file type (e.g. .txt)
4. scroll/head down to shell
5. add new key by creating a folder
6. add your menu there.
Great! you done it. now right click on your file (* or .txt) and see results