Entry items in a ListPreference – how to turn them inactive or grey them out ?

We are a team and have a PreferenceActivity where 3 ListPreferences are present. Each ListPreference has some entries(2 or 3).
We want to show only 1 entry highlighted and the rest greyed out in one of the ListPreference. Can someone let us know as to what changes do we need to do in PreferenceActivity if we change ListPreference to some CustomeListPreference?
Please help us ascertain the clue.