How do I set the reference frame of my robot

Hello all, My understanding is that Gazebo reference frame by default is ENU which heading zero facing easting. I would like to add a robot to gazebo and have it in a reference frame ENU which heading zero facing northing. How could I specify that in Gazebo?, so that when I request the pose of the robot I get it on my reference frame and not in the default Gazebo reference frame.