I believe there is a one-liner using htaccess if you are on an apache server. I don't have the link handy, but I remember when I was first using htaccess there was a command that was a server-type that made a particular file be downloaded with the box-prompt instead of just downloading to the temp directory.
yeah i found it i can do it with this
header('Content-Disposition: attachment; filename=$file');
but this makes the server read the file and then send it to the user. quite banwidth and memory intensive since most of the files won't be on my server. is there anyway to use http header to make the user download from a remote location?