I am using the following RewriteRule, that works fine if the specified folder is public, and does not require a user/pass:
RewriteEngine on
RewriteRule ^/video/(.*) //10.42.1.51/qnap/SessionVideos/$1 [T=video/webm]
However, if that folder is not public, I receive an Error 404. Is there any way to work around this? Like pass in the username/password in the path (eg add @user:pass), or a global setting in Apache that allows to specify credentials when accessing restricted folders?