What's the point? You're utterly removing the efficiency of the spell. GUI to JASS conversion is useful. Backwards is not. You can read the formula to make the missiles move - It has enough description to allow this, and you can obviously use it for a map. If you're expecting some tutorial from this, then look in the tutorial section. That's the point of having one.
Trying to replicate the effects is what you should test yourself on doing - Challenge yourself.