Silverlight, Actions and Prism

When using Prism for composition in Silverlight how do I attach actions between modules?

Am I forced to use the event system or is there a way to set the TargetName for my Actions to the name of a UserControl in a different module?

For Example:

<Image Height="40" HorizontalAlignment="Right" VerticalAlignment="Bottom" Width="40" Source="/SilverlightDemo.MainToolbar;Component/Images/i_chart.png" Stretch="Fill" Canvas.Left="222" Canvas.Top="55">                <i:Interaction.Triggers>                        <i:EventTrigger EventName="MouseLeftButtonDown">                                <Actions:ToggleCollapseAction

                            TargetName="HERE:/SilverlightDemo.Modules.TargetModule;Views/TargetModuleView"                             CollapseHorizontal="False"                             CollapseVertical="False"/>                        </i:EventTrigger>                </i:Interaction.Triggers>            </Image>