Intercept windows open folder

I am trying to make a small app that monitors a folder and when i double click on that folder, it will show a dialog prompting for password to enter the folder if correct password is entered else not.

I am searching for a sample code and info about this but i haven't found anything concerning this.

I have found this as an answer here (http://stackoverflow.com/questions/1...dows-open-file) but am still confused about this.

How is that related to Qt?

I want qt to monitors this folder and when i double click on that folder it open a dialog asking for password.

Qt doesn't do things like that. Look for native API.