The MS-Excel Stream Handler class is designed to demonstrate the use of the stream functions in PHP to write directly to a file, in this case Excel. It was never intended to be a fully functional Excel writer/reader. The design goal of the class was merely to demonstrate stream handling functionality as a mechanism for writing to a specific file type.
There are other alternative PHP classes which write directly to an Excel target using simple file i/o rather than streams.
For those who prefer to stick to the PEAR standard, there is the PEAR::Spreadsheet_Excel_Writer and PEAR::OLE classes. See here for a write up on how to do this:
sitepoint.com/article/pear-spreadsh
...
Another class which is just as, if not more, functional is here:
bettina-attack.de/jonny/view.php/pr
...
Feel free to use these classes as-is, or combine them with the MS-Excel Stream Handler to add your own functionality.
Good luck.