Server side permissions for SaveAs

[Csaba]

I've made a short little script using Excel 2007
on my Windows 7 Home Premium machine.

The script invokes excel, adds a new workbook,
and then attempts to do a SaveAs("Test.xls") on
it (the file does not previously exist).

This works fine from the command line.
However, I have apache running as a server and if I
try to invoke the script as a web page I get an error of:
Unable to get the SaveAs property of the Workbook class

I think the issue is that the excel file can't be written into the
directory.
So I went to the directory using Windows Explorer and I changed the
permissions on my web folder (where I want to write the excel file) so
that all the four groups listed (Authenticated Users, SYSTEM,
Administrators (webpage\Administrators), Users (webpage\Users))
have write permission.

How can I patch this up to be able to save my server side file to
disk?
This particular script is only to be used by administrators,
infrequently.
Also, I am able to write database files and text files in the webpage
directory

Thanks,
Csaba Gabor from Budapest