Hi Frans,

There are several articles about this on the Internet. Several of them have problems.
The most reliable solution I'm aware of is from Jan Karel Pieterse. It is certainly not easy. But try following his recipe:

http://www.jkp-ads.com/Articles/RegisterUDF00.htm

--
Kind regards,

Niek Otten
Microsoft MVP - Excel

"F.H. van Zelm" wrote in message ...
| Hi,
|
| After writing a user defined function, I know how
| - to add a general description
| (like Sum has 'Adds all the numbers in a tange of cells.')
| - to place the function in category
| (with MacroOptions
|
| But how to add a description to an argument, like SUM
| has 'Number1: number1, number2, number3 ... are etc.'?
|
| On www.bettersolutions/excel, I found a complex work
| around by registering the functions.
| Is there a simple way to do the trick? I sure hope so.
|
| --
| Mvg, Frans
|
|