I'm developing a VB6 COM Add-in for Excel on a machine that current has
Office XP installed, which means that my VB6 project sets a reference
to the Excel 10.0 (2002/XP) object library.

I would like my add-in to be backward compatible with Excel 2000, which
uses the Excel 9.0 (2000) object library. In order to ensure this, as
far as I can tell I have 3 options:

1. Check the Object libraries for 2000 and XP looking for any
differences that might effect my code. Then cross my fingers and hope
for the best.

2. Buy and install Excel 2000 in order to get access to the older
library.

3. Obtain a copy of the Office 2000 SDK. Unfortunately, I can't seem
to locate this anywhere on MSDN.

Option 1 looks like my best bet. Has anyone tried this with success?
Any gotchas to watch out for.

Option 2 isn't appealing because of the cost and the configuration
headaches. If I had VPC or VMWare it would be less of an issue, but I
don't have either.

Option 3 would be optimal, but I don't know where to obtain a copy of
this SDK. Does anyone know if there are still copies available for
download?

Any advice would be greatly appreciated.

Thanks,

Nick