I am in the process a of migrating an application which is Excel based with
additional functionality written and installed as an Excel plugin.

I am migrating the application to Excel 2003, with the additional
functionality migrated to using Visual Studio Tools for Office 2005, written
in c#, and adopting the new VSTO 2005 code behind implementation model.

Originally VBA marcos were written to provide a wrapper to expose some of
the functions within the plugin so that these macros could be used as cell
functions within the Excel worksheets. The end result was a way call the
exposed functions provided by the plugin from the Excel.

I have been trying acheive the same thing of exposing my c# methods to be
used as cell function in the new VSTO 2005 code behind implementation model,
but after many days of searching I have found no documentation, news group
postings, or technical article describing or even suggesting how this is
acheived.

Can anyone help point me in the right direction?

Cheers, Neil.