El amante de la luna

I saw this movie on TV in the 80's and loved it. I was a young teen in love myself at the time and totally related. I taped this on a VCR and watched it over and over until the tape broke. One of the things I enjoyed most was the soundtrack, especially the love song which I have been trying to find out the name and artist for over 20 years! I had wanted to use it in 1984 as my wedding song but no band or DJ knew the song or movie... Can anyone help? The song name might be "I'll Love you Forever"?? I am not sure, but it had those words in the song....would appreciate any help. This song was also used years ago in an episode of the soap opera All My Children. It has stayed with me for so many years and when I saw this site I thought maybe I can finally put this lingering question to rest (and use it at my 2nd wedding!) Thank you!