Click Here Drop-Down List

I'm in need of a widget that instructs the user to "Click Here" to make a selection from a drop-down list. Once the selection is made the "Click Here" message changes to display the selection, after which no further selection can be made. Is QComboBox the appropriate widget? If so I can't seem to configure it to work without it looking like a hack. Any suggestions?

Yes, combo box is ok. You can switch it to disabled after the selection is made.