TAdvTreeView ItemIndex of ComboBox of Node

When using the TComboBox as editor for a column like this:
AdvTreeView1.Columns[1].EditorType := tcetComboBox;
How do I get the itemindex the user selected of each node in column 1?
And how can I set the itemindex programmatically?

The ItemIndex is not used, it's the selected text in the combobox that is used to be stored in the node. You can use the OnBeforeOpenInplaceEditor, OnCustomizeInplaceEditor and OnCloseInplaceEditor to determine additional steps happening while editing a node. You could for example store the itemindex of the combobox in the node value DataInteger

procedure TForm26.AdvTreeView1CloseInplaceEditor(Sender: TObject;
  ANode: TAdvTreeViewVirtualNode; AColumn: Integer; AInplaceEditor: TWinControl;
  ACancelled: Boolean; var ACanClose: Boolean);
  ANode.DataInteger := (AInplaceEditor as TComboBox).ItemIndex;

Then afterwards you can retrieve from the node which index has been set.