French Horn Music for "Gabriel's Oboe" from "The Mission"?

I play french horn, and when I watched the movie "The Mission", I immediately fell in love with this piece of music. I have heard it played as a solo on french horn, and the sound that is created when this instrument and piece mix is enough to bring tears to ones eyes. The only problem is-I don't have the music, nor do I know where to get the music! My mom would also like me to learn it, so if anyone knows where online I could get it that would be great! What would be even better if it was free and printable online, but its ok if it isn't. Thanks!