You'd need to change it to "quale" because "qual" is a truncation (apocope) and in informal speech it isn't used before consonants, except in some locutions (e.g. qual buon vento). But that aside, yes, it's fine.
Just out of curiosity Jess, where does the "one" come from in your first suggested translation? I thought it would be "Which is my book?" Is it because the rest of the sentence refers to a single thing?