You can use the Position Probe tab of the Probe Toolbox (View | Other Windows | Probe Toolbox) to position your laser sensor. This tab contains sets of values in two columns.
Left Column: The X, Y, Z values. They show the laser sensor's current position. You can click up and down arrows to change the value in the XYZ Probe Position box for an axis. This moves your laser sensor in real-time by the increment value on the right.
Right Column: The increment values. These specify how much to increase or decrease the XYZ Probe Position box for each axis when you click the up and down arrows on the left column.
Alternately, you can type the XYZ values in the left column, and press Enter to move your laser sensor to a predefined position.