Exporting orchestral (prog) stems for the final mix of a movie: how?



Hi,
I'm currently witing and producing the music for a short (20 min) movie.
This will be mainly orchestral music made with a PC (no real takes will be incorporated).

When people hear my mixes, they all tell me there is no need to add an extra step of "mixing the music".
But someone says to me that it is much better to deliver stems to the final sound ingeneer.

I was told to use LRC format to deliver the stems.

Can someone confirm what format would the final ingeneer is to expect from the producer of an orchestral music? What is usually done?
Is the LRC format usefull indeed?
What other advice could you give me in order to stay effective and to give the engeneer all he/she needs and not more?

Thanks :)

Huey

PS: if there is a more specific forum for sound for movies, I'd be gald to be redirected towardsit

PPS: if you know how to export LRC files from Cubase 5, please let me know. Im' trying and reading the manual, but for the moment I'm not successfull.
.