How to use UDFs ?

[Dignata Mandal]

Hi,

      Can any one assist me how to create user defined function through axlsx gem. My requirement like I want to remove all special characters from a string. I found there is no formula to eliminate special characters in excel but I can do it by using macro's. I can do it by creating macro manually but I need to do by using this gem.

      Could any one can assist me ASAP.

Thanks,
Diganta