I've seen a setup whereby the shooter made up a bracket that mounted the laser 5" above the scope. It looked unwieldy but in effect have him a cheap and reasonable accurate way of rangefinding. The further the laser is mounted from the scope, the better.
Zero both at say 25y and any less and the laser will be higher than crosshair, more and the laser for will be below crosshair.
Simply marking out ranges and recording the results will give you an accurate (If you can see the dot) way of rangefinding.