Field ("variables") in Process Email Templates'URLs (GUI editor)

Hi all,

Is there a way to add custom fields in URL on process email templates. 

I've tried to go on "Insert/edit Link" then set my link to{::Cases::my_field::} , but this will be send as it is, without replacing the field name by its value. I even tried to edit this through the database but the result remain the same. 

Any ideas on how to get this to work ? 

Thank you,