Vista - Trigger Storyboard from c# code

Hello everybody,

I'm currently using a template for a button that triggers a storyboard
animation when moving the mouse over the button. The template looks
basically like this:

....
<ControlTemplate x:Key="GlassButton" TargetType="{x:Type Button}">
<ControlTemplate.Resources>
<Storyboard x:Key="Timeline1" x:Name="Timeline1">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
Storyboard.TargetName="glow"
Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="00:00:00.3000000" Value="1"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</ControlTemplate.Resources>
<Border Opacity="0" HorizontalAlignment="Stretch" x:Name="glow"
Width="Auto" Grid.RowSpan="2" CornerRadius="4,4,4,4">
....

Now I want to trigger the storyboard animation from the c# code as
well. I tried something like

Object o = myButton.FindResource("Timeline1");
myButton.BeginStoryboard((Storyboard)o);

however, this throws an InvalidOperationException pointing out that
"'glow' name cannot be found in the name scope of
'System.Windows.Controls.Button'".

What do I do wrong?

Thanks in advance

Timmy