Mitch, please read the help again. You can enter whatever you want in the filetype box. It comes with some presets like html, but it will save your frequently used choices. Here is a screenshot. I just used it to change the Poser version in my cr2 files that were ProPack. The program is quite capable but like anything else, you can't just run and gun with it.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken