how to make cell = another cell in an online excel workbook

I have a link "http://xxx.com" containing an excel workbook, and I want to make a new workbook in which cell A1 of the new workbook refers to cell A1 of the online workbook at "http://xxx.com". I also want it to be able to automatically update when values in the online workbook change. How do I do this?

My online excel workbook's location cannot be changed and I cannot use web query, are there formulas or macros to help?

Hi
You can only do this if both workbooks are stored in the same domain.
Tony