Mass update Sage CRM - Country Field

Hi 

I am trying to help a client do a mass update of the country field in CRM base on STATE and PC information.

I found this link

https://community.sagecrm.com/user_community/f/84/t/12031.aspx

Which  was very useful but I must have missed something as I still can not see the fields in the mass update screen.

I can see it in the advanced fine.

Does anyone have any tips to add.

Thanks