(As an alternative to the approach described below you should consider using Excel-DNA. Excel-DNA allows you to build a registration-free RTD server. COM registration requires administrative privileges which may lead to installation headaches. That being said, the code below works fine.) To create a real-time Excel automation add-in in C# using RtdServer: 1) Create a … Read more
I looked into this problem again, and the Application.Addins collection seems to have all the addins listed in the Tools->Addins menu, with a boolean value stating whether or not an addin is installed. So what seems to work for me now is to loop through all addins and if .Installed = true then I set … Read more
It is actually possible albeit complex. I am reposting this piece of magic from Kevin Jones aka Zorvek as it sits behind the EE Paywall (link attached if anyone has access) While Excel strictly forbids a UDF from changing any cell, worksheet, or workbook properties, there is a way to effect such changes when a … Read more