If you can make a batch file that can mask its own icon, then use the "two filetypes in one file" trick, I suppose you could get someone to click the file with an image icon thinking they're just opening it in their chosen application but really letting the batch script run. If you could do this, and I mean I've never heard of anything like it working before, you also probably wouldn't be able to have an extension on the file to give its true nature away.