There has been questions going on about making an HDR image out of a single photo and whether it was possible to achieve it. The answer is, yes it is possible by manually adjusting the exposures in photoshop or any other photo editing software and generate it to become HDR with a second software you'll need such as Photomatix Pro or HDR Darkroom. After the generating process you would need to tone map the photo to get the end result you prefer. From there everything should be simple cause the software should do the rest of the work for you. Nowadays, there is nothing impossible to achieve in photography. There are shortcuts that we can take as an advantage but I suggest to always know your basic photography and camera setting knowledge before using these shortcuts. The art of photography apart from the end result itself is the process we do with our cameras, the craftsmanship and how we paint our photos with lights by using our knowledge and skills. Apart from that, the results are usually more stunning doing it the proper way not just in HDR but in all types of photography. Don't be a lazy photographer. It´s a hobby with a beautiful process in learning to master it.
Have fun with your experiment in HDR from a single photo. If you would like to ask me more about how to properly set your camera for HDR please send me an email.