Is a Case sensitive Click Item possible?

Is a Case sensitive Click Item possible?How do i click exactly case while using ClickItem or SelectItem in the combo box items e.g dselect,Dselect.

I need to select the "Dselect" by using the ClickItem e.g object.ClickItem("Dselect"),but the ClickItem is not working in the case of sensitive,the "dselect" is selected.