Try the instructions here, Alejandro:
http://www.vertex42.com/ExcelArticle...functions.html
--
~Anne Troy
www.OfficeArticles.com


"Alejandro Garcia" wrote:

I need create a funtcion and use it in all book, in all sheet. I have
the function but I don't know how use it like, =MyFunction() in
something books.

Thanks.

Sorry, my English isn't good.