I know どれ means "which one?" when talking about more than three items, and I know どっち means "which one?" when talking about two items, but which one do I use when talking about both? For example, let's say there are two Harry Potter books on a table and I don't know which one it is (the one I would be pointing to), so I ask which one. The problem is, even though there are two Harry Potter books on the table, there are seven or eight Harry Potter books in total. I want to know which book it is in terms of reading order. So do I say どっち because there are only two books there, or do I say どれ because in total there are more than two books, even though there are only two in front of me?
I hope this question is clear, and thanks in advance.