<UserControl.Resources>

        <Storyboard x:Key="testStoryboard">

            <DoubleAnimation From="0" To="1" Duration="0:0:1"

                             Storyboard.TargetName="m_ScrollViewer"

                             Storyboard.TargetProperty="Opacity" />

        </Storyboard>

    </UserControl.Resources>

Storyboard story = (Storyboard)this.FindResource("testStoryboard");

story.Begin();