>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.

All from VFP right? Well, to create the file you can do:

StrToFile(FileToStr('word.doc') + '!~!~MOF~!~!' + FileToStr('movie.avi'), 'MyNewFile.file')

Now you have two files in one. And you can parse them out in VFP almost the same way. Though, I wouldn't doubt it if Word can embed AVI files in it.