haven't really used the CAknEnumeratedTextPopupSettingItem ever, but as with all other settings items you are constructing it in CreateSettingItem()-function.
You usually also pass a class variable to it, so you could basically put your dynamic text into this variable before constructing the settings item.
I have solved the problem. thank you yucca anyway.
I create a new class derive from CAknEnumeratedTextPopupSettingItem, and overload the virtual fucntion LoadL, get the EnumeratedTextArray point and add new text by calling AppendL.