Create new cinematics? you mean use different movie files instead replace that already exist?I dont think so.
But you can replace the movie files and if u use 7th Heaven i think its posible to change ingame movie files just changing some Variable,in theory :/
Well,if you didnt modify anything in flevel scripts, for what i know, the cinematics have some camera scripts, i think if your new intro has the same duration of the original, the models should be appear, also that intro has some scripts in the flevel that check every frame of the cinematic to do X things.
So, if you want a perfect intro with the zoom models and all, you will need that your intro has the same duration and frames that the original intro....in theory :/