How can i create my own filetype? I want to 'encapsulate' a word doc and an avi file (or whatever) into a single file with its own extension, and later on open the file and see the file contents. I know i can acomplish this with a .dbf but the problem is that any person could open the file. With my own filetype only the propers functions will open the file. Any idea how can i do this?

Thanks
Héctor L