I just create a new entry.

Action : Add attachment from directory.

Action : Add Attachment fom database.

After, in the "content" area, I used "attachment text link".

In the page, I have the link automaticaly but It open in current browser.

Your solution like " <a href="database.nsf/dx/file.ext/$file/file.ext" target=_blank">test</a> " work but it's not simply for basic user to use.

an option like external link for attachment will be more useful.

A question about translation :

Have you test research résult with special character ?

I test in your base with "Août", and the result page w