Heres how to make it :

Unscrew the back off the laser pen.

Remove the cap off the ink pen and cut the tip off about the height of the three batteries from the laser pen .

Drill a hole in the tip of the ink pen cap and drill two holes through the back of laser pointer.

Cut off the USB Adapter plug and add as much wire as desired.

Feed wires through the Laser Pointer back piece.

The negative line ( - Vdc ) goes through the ink cap .

Solder the negative line with a little extra solder to make it round and big enough, so it cannot fit back through the ink pen cap.

Wrapped the positive line ( +Vdc) inside the laser pointer cap, making sure that it was a tight fit and let friction keep it in there .

Pull the Negative line ( -Vdc )wire and let the the cap slide over the ball point pen cap.

Super glue all this together.

This will fit most store bought generic Laser Pointer .