Silverlight SetTargetProperty of a Custom User Control

<usercontrol x:class="Coach2D_SL.UC1" xmlns:x="#unknown">
    Xmlns … >

    <stackpanel x:name="Sp" background="Transparent" margin="100,100,0,0">
        <border name="Border1" background="transparent" borderbrush="transparent" borderthickness="2" x:uid="mbi">
            <grid>
                                           Width="56" Height="56" />
            </grid>
        </border>
    </stackpanel>
</usercontrol>

Partial Public Class UC1
    Inherits UserControl

    Public WriteOnly Property Position As Integer()
        Set(value As Integer())
            Sp.Margin = New Thickness(value(0) - image1.Width / 2, value(1) - image1.Height / 2, 0, 0)
        End Set
    End Property
 
    Public WriteOnly Property RotationAngle As Double
        Set(value As Double)
            Rotate.Angle = value
            image1.RenderTransform = Rotate
        End Set
    End Property


End Class

. . .
    xmlns:uc1="clr-namespace:SilverlightApplication1"
. . .

Imports SilverlightApplication1.UC1
 
Partial Public Class MainPage
    Inherits UserControl

    Dim Uc1 As New UC1
  Private Sub Canvas1_Loaded(sender As Object, e As System.Windows.RoutedEventArgs) Handles Canvas1.Loaded

      Uc1.Position = {70, 150}
      Canvas1.Children.Add(Uc1)
End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles Button1.Click
 
        ' Prepare animation
        Actpts_X = New DoubleCollection
        Actpts_Y = New DoubleCollection
        ActAng = New DoubleCollection
        '
        Dim Anim_X As New DoubleAnimationUsingKeyFrames
        Dim Anim_Y As New DoubleAnimationUsingKeyFrames
        Dim AnimAng As New DoubleAnimationUsingKeyFrames
        '
        Dim d As New Duration(TimeSpan.FromSeconds(T))
        Anim_X.Duration = d
        Anim_Y.Duration = d
        AnimAng.Duration = d
        ' Create Frames 
        For i  = 0 To PolyLine1.Points.Count - 1
            Actpts_X.Add(PolyLine1.Points(i).X - Canvas1.Margin.Left)
            Actpts_Y.Add(PolyLine1.Points(i).Y - Canvas1.Margin.Top)
            Anim_X.KeyFrames.Add(New DiscreteDoubleKeyFrame() With { _
             .Value = PolyLine1.Points(i).X, _
             .KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromSeconds(i / speed)) _
                })
            Anim_Y.KeyFrames.Add(New DiscreteDoubleKeyFrame() With { _
             .Value = PolyLine1.Points(i).Y, _
             .KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromSeconds(i / speed)) _
                })
            AnimAng.KeyFrames.Add(New DiscreteDoubleKeyFrame() With { _
             .Value = RotAng(i), _
             .KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromSeconds(i / speed)) _
                })
        Next


        Dim SB As New Storyboard
        Canvas1.Resources.Add("unique_id", SB)
        SB.Duration = d
        SB.Children.Add(Anim_X)
        SB.Children.Add(Anim_Y)
        SB.Children.Add(AnimAng)
        '

        Storyboard.SetTargetProperty(Anim_X, New PropertyPath("(Uc1.X)"))
        Storyboard.SetTargetProperty(Anim_Y, New PropertyPath("(Uc1.Y)"))
        Storyboard.SetTargetProperty(AnimAng, New PropertyPath("(Uc1.Angle)"))
        '
        Storyboard.SetTarget(Anim_X, Uc2)
        Storyboard.SetTarget(Anim_Y, Uc2)
        Storyboard.SetTarget(AnimAng, Uc2)
        '
        SB.Begin()
 
 
 
    End Sub