Hi KSue,

In Punch a retaining wall is just a wall, without additional properties.
There is not a exact procedure to solve the problem, but instructions and work around to achieve your goal
- To follow the topography--> select the wall--> Edit--> Float object above topography
- To stop the topo go through the wall: this happens because Punch need a closed perimeter of walls--> to avoid this you can create a closed perimeter of walls, your retaining wall with the right height and the other walls with height= 1"
- You can work with separate berms going close to the wall--> to simulate the surface touching the wall, use the filling tool (landscape tab) or the floor tool and texture as necessary

Let us know if you need additional help

Patricia