I don't think anyone does. You'd probably have to:

1. Cut out a very hard piece of material in the precise shape of the shoe insole.
2. Cut out enough of the shoe, at the ball of the foot, for the clip.
3. Remove the shoe insole.
4. Place in your new insole.
5. Somehow drill or cutout holes in the new insole for the screws.
6. Replace the old insole.
7. The clip will probably stick out still.

The material is probably the hardest part. Maybe plywood? Probably wouldn't work nearly as well as the hard plastics/carbon fiber used in cycling shoes.

If you have any luck with it, tell me. I'd love to turn a $20 pair of target sneakers into spd shoes instead of spending $100.