I'd like to know that myself!

As a workaround I use "Selection" which returns something like

"[myBook.xls]!R1C1"

then I get the filename between the brackets

Regards,
Peter T

"The Chemist" <The wrote in message
...
I developed an application years ago that uses DDE to converse with Excel.
I
used to be able to send a DDE request using the topic "TOPICS", and it
would
return a string that contained the name of the spreadsheet file that was
currently open. Now, this command returns an error with Excel 2003. Any
ideas??