First I think you mean 720p.
Second, the wii can NOT play 720p aka .mkv/.h246 or whatever its called. The wii processor can not handle it so it will skip when you try to play it. There is really no software to force something that has a max output of 480p to display 720p. I can be wrong about that though cause I have heard talk about people playing NSMB in 1080p so it can be plausible.