Hi there,

I am fairly new to all of this and have a big problem that I hope someone 
more skilled than I can help me with (in particular help me understand:)

I would like to write an add-in (not sure whether it has to be
automation or COM?) that opens a separate window  (as defined by the
C# add - in) in Excel once the user executes a macro. The window
should have a button that when clicked displays the contents of the
selected cells (i.e. I need to give the user the ability to read in
data easily so the add-in can process it). Again, the new window should be 
defined by the c# add-in, not a VBA form. I found this article and tried to 
follow it:

http://www.dotnet247.com/247reference/msgs/40/203206.aspx

.... but unfortunately ran into trouble. In particular, I have lot's of 
issues with 
references not being found in
the example given above, even after adding the XP PIA's as project
references and providing the 'using Microsoft.Office.Interop.Excel'
directives.

Can someone help me and shed some light and maybe send me a brief example? 
I'm using
the Visual Studio Express edition for now so the more extensive your
explanation the better as I suspect it doesn't do everything VSTO
does.

Many thanks!