Hi! The sentence is not completely right. I'm sorry but it doesn't make much sense. I guess one possible form could be:
"En algún lado más allá (del final) del arco iris"
That means: "Somewhere over the rainbow". There is a famous English song which has this title. It was originally singed bu Judy Garland in the film "The Wizard Of Oz"
Many Greetings!
Saludos!