How to set property having data type foreign as keyed name of itemtype

hi i want to set property as keyed name of item type but property data type is foreign i create item A having property "bal_part" which data type is item having data source Part item create another property "bal_partname" which data type is foreign having data source Part item and foreign property "name" of bal_part i set keyed name of item A as 1 for "item_no" of property  and 2 for "bal_partname"  property of Item A but in keyed name it only shows item_no, not showing name of Part Item