I've seen this addressed a number of times but have yet to see a
satisfying answer - how do we add a persistent Excel toolbar menu item
from a Automation Add-in?

I've built an Automation Add-in that also implements the optional
IDTExtensibility2 interface (in order to take advantage of start up
events). I create a menu item from the OnConnection() method. Here's
what happens:

1) Run Excel.
2) Begin to insert a formula. (OnConnection() doesn't fire until I
enter the first character after the equal sign (e.g., =A))
3) OnConnection runs and installs my menu item.
4) Menu item remains on the toolbar while Excel runs.
5) Save the spreadsheet, quit out of Excel.
6) Run Excel, open saved spreadsheet, menu item is gone...

I'm looking for my menu item to be persistent and to be displayed
either when I start Excel, or when I open a previously saved
spreadsheet from which the menu item had been installed.

What's the proper way to achive this behaviour? (FWIW, I'm using Excel
2003 and C#/.NET)

Thanks,
Steve