Hi there,

How can I write a function that is available as a formula on a
worksheet in a VSTO/code behind a sheet solution? I am aware of
automation add-ins but these functions are meant to retrieve data from
a pre-populated object and if I write a simple automation add-in then
the data object would have to be re-created for every function call,
which is slow.

Ideally, I would like my solution to start up with the sheet, attach
to the data source, go and populate the internal data object and then
selectively load certain template workbooks/sheets that have my
formulae in them. As the formulae get executed they access the pre-
populated data object. How can I do this?

Thank you very much,

C.