I'm using cPanel and trying to prefix all my download links so that instead of downloading PDFs and docs, users can view it. E.g. mywebsite.com/downloadme.doc becomes googledocviewer.com/something?=mywebsite.com/downloadme.doc (I don't know the actual site Google uses for their doc viewer API atm)
You should be able to make a rewrite rule using .htaccess file to accomplish this on particular file types/extensions for example.