xamDataGrid and Combobox (how to access cbx?)

Question

Hello Experts,

I am using a xamDataGrid (Infragistics), one Column has to contain a combobox. The items in the combobox are computed, based on the data entered in teh cells before.

How can I access the combox in the ActiveRow ? Thats the XAML:

                            </ComboBox>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </igDP:FieldSettings.CellValuePresenterStyle>
    </igDP:FieldSettings>
</igDP:UnboundField.Settings>