Hi all,

I've been maintaining an application that currently runs in Excel
2003, with tons of VBA code and a couple of VB6 ActiveX dll's
underlying that which implement some business logic and database (SQL
Server) access. The VBA app contains some custom forms which display
inside Excel.

I've nosed through the (confusing) documentation on Microsoft's sites
regarding the various versions of Office and VSTO, but I'm still left
with some questions. Could someone please clarify or answer the
following, or point me to a decent source of information.

1. My main question is with regards to the possible upgrade paths
available to us, from the existing Excel 2003/VBA/VB6 ActiveX/SQL
Server solution to EXCEL2007/VS2005/VB.NET/SQL.
It would appear that I can replace the VB6 Ax controls with an add-in
written in VB.NET, but that all the macros inside the Excel workbook
would still have to be written in VBA. The same goes for the custom
forms that show up inside the Excel sheets - their code-behind logic
must needs still be done in VBA.
To summarise: all that has really changed in the move to XL2007, is
that we can now replace VB6 ActiveX modules with add-ins written in
VB.NET/C#. Is this correct?

2. What are the benefits of replacing the VB6 Ax modules with .NET add-
ins?

3. Are there any other possible coding scenarios for XL2007 apps?

Many thanks,
Tian