Solution : https://service.sap.com/sap/support/notes/560163 (SAP Service marketplace login required)
Key words :
activity confirmation process batch' data type char12, activity confirmation process batch' data type -> domain, configuration data process batch processing fields, activity confirmation' data type -> domain, database table mill_pc_conf_ short text, process batch activity confirmation heading, - start transaction se11 - enter mill_pc_lz, process batch activity confirmation 4, table mill_pc_conf' import parameter, 'tv_image' field label short