>We are attempting to make an automatic backup application. The application zip up files, and send the zip to server across the internet. Logic tells me the best way is to use FTP. But the client refuses on agree. They want to create drive mapping and simply copy the backup to the server. I never knew this could be done. How would one do this?

Check WebDrive http://www.webdrive.com/. There's a free old version called NetDrive available on Internet. For example, http://www.acs.uwosh.edu/novell/netdrive.htm