Slideshow composer

Basically, a slideshow just show all the photos in a folder and its subfolders.
Are there any ways to compose your slideshow based on single images located in different folders or simply an extract of single images from a certain folder?
– I need to use the same images to multiple slideshows and not having to have multiple copies of the same image lying on my hard drive – so I would like to hear if the above is possible, and how do I do !