how do I use a function from an addin in my vba code. For example, I have
the "Analysis ToolPak - VBA" addin installed and I want to do something
like:

NumOfDays = worksheetfunction.networkdays(startdate,enddate,my range)

this line of code doesn't work because networkdays is in the "Analysis
ToolPak - VBA" addin, not the standard worksheet functions.