Making intranet site, need to open local server files from original folder,

I am making this local intranet site where I work. Each department has their own set of powerpoint slides that are updated weekly for our meetings. The site opens these files, which are located on the local share server, but it does it like opening any file from a browser meaning it is saved to the temp folder for viewing/editing. I need it to open up from the original folder so that when people open it from the site they can edit it and save without having to respecify a place to save it. Any help would be great.