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wrote in message ...

I think that when you open a new instance of Excel from another MS App the
Addins do not get loaded.

That ius exactly waht I said, which is why I suggested forcing the load. I
was able to reproduce your error, not from MSProject but from automation,
and by installing the addin, it worked fine.

In this case I am using MS Project to load Excel.
I have just noticed that when I type in MyApp.worksheetfunction then press
the '.' button for a list of methods/property parameters (?) it doesn't
list
networkdays.

Networkdays is not a worksheetfunction, it is part of the Analysis Toolpak,
so you won't see it, even from within excl