Pick and Place using Moveit

I am attempting to do a pick and place using a custom robot. I am using these scripts as my reference: https://github.com/DebasmitaGhose/moveit_tutorials/tree/kinetic-devel/doc/pick_place https://github.com/ros-planning/moveit_tutorials/blob/indigo-devel/doc/pr2_tutorials/pick_place/src/pick_place_tutorial.cpp I plan to use 2 hands with 2 end effectors to grasp a big object. So, how do I specify the reference frame for the pre grasp approach and the post grasp retreat? Also, how do I specify the position of the end effector for pick and place, since the two hands are at two different coordinates with respect to the robot.