how to upload a remote file to dropbox cloud using php?

Hi I am wondering how I can upload a remote file to dropbox cloud without having to download the remote file to server that run the php script then upload it to dropbox? I want to eliminate the download phase ! (File size of 200 mb)could anyone show me how this can bne done using php?looking forward for replies.

Remote file: a file that I have its url and it is not stored in same server as my php script and it is stored in web in a remote server.

Note;I don't want ftp solution!

I think dropbox uses their own type of file transfer protocol, which means you can't (easily) do it in PHP.