No es ni se usa en español. Ver ingles/which%20one.
"So many songs which one is mine, one must be right for me. Which song of all the songs when there's a song for every star."
Termino en ingles, parte del grupo de palabras de preguntas WH
Sinónimos de which one son cuáles
"These are my keys. Which ones are yours? / Which ones are they?"