Interact with Spreadsheet cells from Excel Addin - C# .NET

Using Visual Studio tools for Office (2005), I'm trying to develope a C# .NET module that will interact with my C# server which updates live stock quotes.  I can easily interact with my module from Excel, but I have 2 problems:

1) I'd like to create an Excel RTD module in C#, so that I can embed custom formulas into cells, that will be updated in realtime.
2) From an Excel Add-in, I can add my menu to excel, and interact with it, but I cannot write a number into a spreadsheet cell.  Every example I've seen looks like:
         Excel.Range rng = Globals.Sheet1.Range["A1", missing];
         rng.Value2 = "socket state: " + state;
My problem is that I don't know where the Globals static object is defined.  The wizard I used to create an Excel addin created a Globals object that does not contain a Sheet1 variable.  Where is this thing defined? and how can I use it, or is there a better way to poke text into a spreadsheet using an Excel Add-in?

Thanks,
GerryStart Free Trial