How to delete the enum value at run time

If I need to delete the enum value at run time then what i need to do?
Example has 3 values
Enum::value1
Enum::value2
Enum::value3

You need to overview the enter event of control from design and write the following line.
combobox:enter()
{
      super();
     this.delete(enum2str(Enum::value2));
}