I have a Dish VIP722K DVR. I currently don't have an external hdd, but I'd like to know if I can add one for viewing my own content. In other words, not for additional recording space, but can I copy my own video files onto an external hdd, plug it into my 722K, and play the videos on tv? I currently have both AVI(xvid) and MP4 files, can also get mkv or convert to other formats if needed.