Event hundler to control the Excel function arguments

[Yattabi]

Hi,
I am writing a function (in an add-in) which will be used in Excel
worksheet’s formula. I want to know if it's possible, to write an event
handler witch will be executed when the user enter each argument in “function
arguments window†of the “Insert function wizard†for my new function in
order to carry out some controls and lookup operations.

Thanks in advance.