add multiple mac in to attribute radiusCallingStationId

hello friends have implemented a server frreeradius get LDAP attributes, what I need is to add multiple mac addresses to radiusCallingStationId attribute. I tried adding the following line in the file ldap.attrmap operator = ~ and separating comma MAC addresses but does not work for me. If anyone has implemented this by I ask for your help, thank you very much in advance.