Variables to use as axis max/min in data table graph builder script

[#1]

I have the following lines in my script I am saving to the data table and then running to make a graph builder graph. When I run the graph from the script it uses the variables as the max and min for graph builder but if I run the script saved to the data table (say I give the table to someone else) it uses default max and min instead. Any recommendations?

min_val = col min(:col1);
max_val = col max(:col1);

// rest of graph builder function not included

Dispatch(
			{},
			"Y Axis Name",
			ScaleBox,
			{Min( min_val ), Max( max val )}
		)

I've tried several things but creating min_val and max_val as table variables and passing those to the dispatch felt like the most promising but no luck - defaults min and max are instead used.

Thanks in advance!

[#2]

The Send to Report() and Dispatch() functions are intended to be used by JMP to save user customizations in a platform. The scripter should instead send messages directly to the object.

Names Default to Here( 1 );

// get example
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );

// pre-determine new scale
y min = 80;
y max = 100;

// launch Graph Builder
gb = dt << Graph Builder(
	Size( 534, 456 ),
	Show Control Panel( 0 ),
	Variables( X( :height ), Y( :weight ) ),
	Elements( Points( X, Y, Legend( 3 ) ) )
);

// get reference to report layer with display boxes
gb rep = gb << Report;

// send cascade of messages to y axis
Wait( 3 );
gb rep[AxisBox(2)]
	<< Min( y min )
	<< Max( y max );