The constrained object’s position is driven by the target point, but you can offset the constrained object’s position from the target point. To do so, edit the Offset and Offset Polarity attributes with the Attribute Editor.
To offset constrained object’s position
By default, these attributes are not displayed as channels in the Channel Box. If you want to control them from the Channel Box, you can add them by using the Channel Control editor (select Window > General Editors > Channel Control).