I'd like to write some addins to replace some user-defined
functions I created in VBA for Excel by C++ COM. Now that
I have all MSDN universal softwares, I want to know how to
do this. Any suggestions?

My needs:
1. The add-ins will be installed on PCs with Excel 2000
only, without additional VS, VB, VC VSOT tools.
2. VSOT for Excel 2003 can't be used.
3. Want to use VC++, because VB is not fast enough.

The problem is that there is very limited references on
this subject. I searched MSDN discussions and technical
papers, and found the following with questions:

1. Most VC++ Add-ins focus on Office 97 with VS6 as tools,
and are probably dated. But that is where most the
discussions are. I have no problem using VS6 as tools.

2. More recent and sigificantly newer tools are for Office
2000. There is a VB Programmer's Guide. But less
discussions on VC++ as a tool rather than using VB with
Office 2000 Developer.

3. More recently, there is Office XP Developer. Is this
much better than Office 2000 Developer? Is it true that
both are for VB as a tool, not for VC++ or other tools?
Can I use Office XP Developer to create C++ Addins and
install them for Excel 2000?

4. Officially, Office 2000 and XP Developers have been
discontinued, due 2001 legal settlement. I own them so I
can still use them.

5. Visual Studio Tool for Office (VSTO) from VS . Net 2003
is supposed to replace the Office Developers, but can not
be used for anything other than Office 2003 Pro, which
really limited it use. Correct?