How to implement something similar to enumeration member completion?

I have a class called SubjectState where one of the properties (ageCategory) refers to an enumeration class (AgeCategory). If I want to assign the property value of the ageCategory property in the command line I can use tab to see all the enumeration members and do autocompletion.

This is a very nice feature, but for a couple of reasons I do not want my AgeCategory class to be an enumeration class. Is it possible to specify the enumeration members in a list on a constant property of the AgeCategory class instead of using an enumeration block and somehow retain the autocompletion which is illustrated in the screenshot below?