I don't think you can do that. A LabVIEW enum includes the string names as part of the data type. You cannot change the data type of a control or indicator programatically.
If you use a TEXT RING or a MENU RING, then you can get approximately the same behavior - you can set the STRINGS property of either to an array of string values. The difference is that the VALUE of the control is a numeric, not an enum. If you wire the control to a CASE statement for example, the cases would be 0,1,2, where a true enum would have "A", "B", "C" cases.
