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!

Somewhere over the rainbow

Hay un arcoiris en algun lado mas allá al final