I could say you don't need any script for that...
All you have to do is Pass the Data in the Other game to a new Project, (Except the Maps unless your planning to use them in the new Chapter)
Make a Black Map at the End of the Credits asking the player to save the Game.
you only need to pass the Save file to the New Project/game which is the Second or so chapters. Note that you have to put that Same Black Map in the New Project, otherwise you might get a lot of bugs =/ and make sure all the Data is in there...errors tend to always appear.