There's information on compound documents in the following article:

Using a Dual File Format in Excel
http://office.microsoft.com/en-gb/as...381621033.aspx


Wetcoast40 wrote:
I receive Excel files via e-mail from my head office that can't be opened
with Office xp. As close as I can tell, these files are called "Compound
Excel Files". I can't find any explanation of what a Compound File is and
why I wouldn't be able to open it. In addition, when I notified the office,
they cut out the pertinent information segment of the file and re-sent it.
Surprisingly, I was able to open it. They claim they didn't change the
format or program.



--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html