The following VBScript example demonstrates the use of Word's object model. It adds a filled rectangle to the message area of the item.
Sub CommandButton1_Click()
Set myInspector = Item.GetInspector
Set WordDoc = myInspector.WordEditor
Set Fill = WordDoc.Shapes.AddShape(1, 90, 90, 90, 50).Fill 'msoShapeRectangle=1
Fill.ForeColor.RGB = RGB(128, 0, 0)
Fill.BackColor.RGB = RGB(170, 170, 170)
Fill.TwoColorGradient 4, 1 'msoGradientDiagonalDown=4
End Sub