Thank you for your answer. Such folder did not exist, so I created it and placed the DLL inside: C:\Program Files (x86)\Notepad++\FileTypes, however, I don't see new option: http://screencast.com/t/OrU7lKK6rogC
Furthremore, should I save the base64 string in a file and open it with this extension. And if so, what the file extension should be?