Another, usually faster, way of splitting a string is with a Tally (or numbers table) see Jeff Moden's article in my signature below.
Take a look at the method about three quarters of the way through the article, where he compares the loop method with the tally table method you will see that he inserts the results into a temporary table which includes an IDENTITY column. This IDENTITY value can be used in a where clause to get the nth item.