Hi Mark_W, I guest the easiest way to identify what Framebox you are assigning the instruction in your script is the following:
First create the graph using graph builder (not using the script for now) assigning properly the (height, weight and sex accordingly to the analysis you want), after creating the chart, select Done to finish the analysis.
Right Click the gray triangle in the upper left corner and select Edit, Show Tree Structure, it will display all the components involved in the visualization of your chart with the corresponding names by default to each component, from there you just move your pointer across each component in the Tree Structure and you will see how the chart is selected also as both are interactively connected.
After you identify the corresponding name to the section you want to assign a specific line, then you can use the script to edit it.
Hope you get it.