In answer to the follow-up, BQL is the best method for obtaining an index's constituents from Bloomberg (Bloomberg Query Language). The Bloomberg toolbar has an option called "BQL Builder," or you can utilize the Function Builder (the syntax is slightly different).
For the OP's question, enter this formula in a cell:
=BQL("members('SPX INDEX')","ID_ISIN")
It will expand and show all the members of the S&P and their ISINs.