Here is what I would suggest. First clone the route in 2012. Then open the clone for edit in CMP and change the build version from 3.6 to 3.3. Save and commit. Next, convert the cloned version to a CDP and send it to your downloads folder or a similar location. Lastly, start CMP in 2010 and use import CDP to bring the clone into 2010. CMP should install the route in 2010.