You can use the Dimensions tab of the Surface Milling Properties dialog to change which surfaces are machined.
The Dimensions tab has two buttons that open dialogs where you select surfaces to manufacture, and surfaces to use as protected areas where the tool must not go.
Part surfaces — Click this button to open the Select Part Surfaces dialog.
Check surfaces — Click this button to open the Select Check Surfaces dialog.
Cut feature using Y Axis coordinates — In Turn/Mill, 4 axis, or 5 axis parts with Z-indexing, select this option to cut in X and Y, or deselect it to rotate the part about the index axis.
C Angle — If Cut feature using Y Axis coordinates is selected, enter the spindle C angle at which to cut the feature.