AFAIK, no one has translated the song "properly." But I'm trying to teach myself some Japanese, and my best guess is here:http://echoalpha.com/Japanese/ElHazard_SeifukuOuJinnaiKatsuhiko.html(missed the 10th anniversary, and still too busy for fanworks, but at least I'm lurking regularly again)
And here is an MP3 of a friend of mine singing lyrics based on MrWhat's translation:http://www.el-hazardonline.net/download_temp/JinnaiThemeMP3.mp3