Alright, it's a day later than I promised (thanks to my memory stick corrupting the source code files when I first did it
), but here it is!
A simple command prompt utility that does exactly what Naulahauta's diagram explained, nothing less and nothing more.
Just bear in mind that I only had that one file to test with, so I don't know how buggy it is. It doesn't do much error checking, so make sure you have it set up right or you could get unexpected results
And I also have nothing to open the resulting files with, so I don't even know if they've been done correctly
But I'll leave that to you to try out.
Just run it in a command prompt and it will tell you how to use it.
EDIT: Removed buggy version, see later post for up-to-date version