No you cannot, not in VBA, the UDF has to be in the standard code module.
You can call a class from within the UDF, but not directly as the UDF.
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__________________________________
HTH
Bob
"Leo" <(E-Mail Removed)> wrote in message
news

3A0FC3E-6D59-4454-9BCF-(E-Mail Removed)...
> Dear Experts,
> I recently became interested in style of using Class Modules.
> I need to know if we can use Class Modules to creat User Defined
> Functions?(functions that is useable in Excel sheet like a normal
> worksheet
> function)
> if yes, please explain how, and show a simple sample.
> thanks in advance.
> --
> Thans & Best regards
> Leo, InfoSeeker