I am trying to create an Add-in with a library of functions, i.e. Add(num1,
num2) that can be used in my excel workbooks. I am able to do this
successfully, however I can not find any resources on Microsoft's site on
how to add the help text to the formula dialog that pops up. For example,
when you hit the formula button and select the formula function "Sum", there
is some help text that tells you what the function does: "Adds all the
numbers in a range of cells" as well as what it is expecting in the
parameter: "number1, number2, ... are 1 to 30 numbers to sum. Logical values
and text are ignored in cells, included if typed as arguments."

Can anyone tell me how my add-in functions can add this text to my custom
functions? Are there any Microsoft KB articles that covers this?

Thanks,
Bryan