How do I modify a relationship when they have a Long Name?

How do you modify a relationship In the new Royalty & Legacy Pack, hen they have very long names ... Like ....Grand Duchess Cordelia Thebe V,    usually its  ....   

modifyrelationship lee grand marie grand 100 LTR_Romance_main   This is the usual way to do it but when they have a very long name how it is done Please .    Thank You to all Assistance :)

Im on a iMac   Chip M4