Code:
Function AddSurfaceTextureSymbol(sRa As String) As Boolean
    AddSurfaceTextureSymbol = False
    ' Set a reference to the drawing document.
    ' This assumes a drawing document is active.
    Dim oDrawDoc As DrawingDocument
    Set oDrawDoc = ThisApplication.ActiveDocument    ' Set a reference to the active sheet.
    Dim oActiveSheet As Sheet
    Set oActiveSheet = oDrawDoc.ActiveSheet
    Dim obj As Object
    For Each obj In oDrawDoc.SelectSet
        If Not TypeOf obj Is DrawingCurveSegment Then
            MsgBox "Es dürfen nur Kanten ausgewählt werden!"
            Exit Function
        End If
        ' Get the mid point of the first extension line of the dimension
        Dim oMidPoint As Point2d
        If obj.Parent.CurveType = kLineCurve Then
        Set oMidPoint = obj.Parent.MidPoint
        ElseIf obj.Parent.CurveType = kCircleCurve Then
        Set oMidPoint = obj.Parent.CenterPoint
        Else
        Set oMidPoint = obj.Parent.StartPoint
        End If
        ' Set a reference to the TransientGeometry object.
        Dim oTG As TransientGeometry
        Set oTG = ThisApplication.TransientGeometry
        Dim oLeaderPoints As ObjectCollection
        Set oLeaderPoints = ThisApplication.TransientObjects.CreateObjectCollection
        ' Create a few leader points.
        'Call oLeaderPoints.Add(oTG.CreatePoint2d(oMidPoint.X + 10, oMidPoint.Y + 10))
        'Call oLeaderPoints.Add(oTG.CreatePoint2d(oMidPoint.X + 10, oMidPoint.Y + 5))
        ' Create an intent and add to the leader points collection.
        ' This is the geometry that the symbol will attach to.
        Dim oGeometryIntent As GeometryIntent
        Set oGeometryIntent = oActiveSheet.CreateGeometryIntent(obj.Parent, kMidPointIntent)
        Call oLeaderPoints.Add(oGeometryIntent)
        ' Create the symbol with a leader
        Dim oSymbol As SurfaceTextureSymbol
        If sRa = "Ra6,4" Then
            Set oSymbol = oActiveSheet.SurfaceTextureSymbols.Add(oLeaderPoints, kBasicSurfaceType, False, False, , (sRa), , , , , , False)
        ElseIf sRa = "Ra25" Then
            Set oSymbol = oActiveSheet.SurfaceTextureSymbols.Add(oLeaderPoints, kBasicSurfaceType, False, False, , (sRa), , , , , , False)
        Else
            Set oSymbol = oActiveSheet.SurfaceTextureSymbols.Add(oLeaderPoints, kMaterialRemovalProhibitedSurfaceType, False, False, , , , , , , , False)
        End If
        AddSurfaceTextureSymbol = True
    Next
    Debug.Print "ErrNr.:" & Err.Number & " - Desc.: " & Err.Description
End Function