[thelist] php to xls with tabs

I have created a site for a client where employees log-in and enter their
hours etc. in the database and then their bosses can log-in and download the
data in Microsoft Excel format.  That was all fine - I just had a basic
script which downloaded the entire contents of the db to a simple
spreadsheet.

However the spreadsheets now need to consist of 4 different tabs with
different data being entered into the correct tab.  I can see that it would
have to be more complicated than just a simple db dump to an xls file.  I
have not been able to find anything like this on the net or in any books -
and so really I'm wondering if it's possible and if so if anyone could guide
me to the right place to find it?

Thanks

Reuben