The attached document contains the macro “Change Shape via Matrix”. It reads the
property “Transformation” from the selected shape, multiplies it with the matrix
(1 -1 0   1 1 0  0 0 1) (read row wise) and writes the result back to the
property. When applying the macro, the shape should perform a 45°-rotation and
enlarge with factor sqrt(2). So when applying the macro twice you get a shape,
which is rotated with 90° and has double size.
Set a break point in the macro “Examine shape” and watch the object “oShape” to
see this property.

Open the document and select the line. Apply the macro several times. Watch that
the line rotates but does not enlarge.

You can proof that the macro works correctly, when you apply it to a rectangle.