You can now set an instance list column's caption at run time using avListManager.avSetColumnCaption. For example:
#AVLISTMANAGER.avSetColumnCaption Ucolumntype(V) Ucolumninstance(2) UCaption(' My new column heading' )
Will change the header of instance list column Visual ID2 to 'My new column heading' .
Note: Only the standard instance lists VF_UM040O and VF_UM044O will respond immediately. How contact card style instance lists respond will depend on how they are coded.