Hide Combo Box Entry

I have an entry in my combo box (dropdown list) which I use as a default or error value. I don't want this entry to show up in the list when the user is selecting an entry. Is there a way I can have that entry hidden to the user but selectable in my code or do I have to repopulate the combo box each time?

Just use the .Text property of it. That way, if a user doesn't select anything, that value will be used.

I can't. The text property is not writeable during runtime or design time when a combo box sytle is a dropdown list.