How to change plot area size of a shape pasted from an Excel file to a powerpoint?

[Adam Brave]

Hi!
I'm using the code below to copy paste some charts from an Excel file to a PowerPoint file. The macro is running from the Excel file. It works fine. I would like now to be able to adjust a little bit the plot area of the chart after it has been pasted on the powerpoint and not the whole size of the shape. In the code below I'm already adjusting the shape but all my attempts to adjust only the plot area failed.

Sub CopyChartFromExcelToPpt()
    ' Turn screen updating off to speed up your macro code. You won't be able to see what the macro is doing, _
    but it will run faster. Remember to set the ScreenUpdating property back to True when your macro ends.
    Application.ScreenUpdating = False
    Dim PPT_object As PowerPoint.Application
    Dim OpenPptDialogBox As Object
    Dim oCht As Chart
    Dim MyShape As Object
    Set PPT_object = CreateObject("PowerPoint.Application")
    Set OpenPptDialogBox = PPT_object.FileDialog(msoFileDialogOpen)
    ' Open the target PPT using dialog box:
    If OpenPptDialogBox.Show = -1 Then
        PPT_object.Presentations.Open (OpenPptDialogBox.SelectedItems(1))
    End If
    ' Copy the chart from excel macro file
    ActiveSheet.ChartObjects("Chart 3").Copy
    ' Paste the chart in  slide 4 of PPT
    Set MyShape = PPT_object.ActiveWindow.Presentation.Slides(4).Shapes.Paste
    ' Change the position of shape, its height and width
    With MyShape
        .Left = 17.25
        .Top = 68.2307
        .Height = 198.5074
        .Width = 662.414897
     End With
     ' Copy the chart from excel macro file
     ActiveSheet.ChartObjects("Chart 6").Copy
     ' Paste the chart in  slide 4 of PPT
     Set MyShape = PPT_object.ActiveWindow.Presentation.Slides(4).Shapes.Paste
    ' Change the position of shape and its height and width
    With MyShape
        .Left = 17.25
        .Top = 273.2619
        .Height = 198.5074
        .Width = 662.414897
    End With
    ' Save and close the file
   PPT_object.ActivePresentation.Save
   Application.ScreenUpdating = True
   PPT_object.Windows(1).Close
End Sub

Any help here, please?

Thanks in advance

[Adam Brave]

Update:
I tried to use the code below to change the plot area but it is throwing the error "Object doesn't support this action" when it reaches the .Chart.PlotArea.Height = 90 line.

Dim PPT_object As PowerPoint.ApplicationWith PPT_object.ActiveWindow.Presentation.Slides(4).Shapes.Range
If .HasChart Then
     .Chart.PlotArea.Height = 90
End If
End With

Can someone help me to understand why this line is giving this error?

Thanks