QRCode > to password protected directory

Hi, i need some help building a script. I have a public facing website but want to htaccess (or php) deny access to a number of folders from the public. I need to be able to access the contents of a folder only via a QR code. Please can you quote on create this script for me... I have the QR codes to the webdirectories but somehow need to pass basic authentication through from the qr code to access the site within the folder. I hope this is clear.