Hi,
 
Sort of like this:
 
Names Default To Here( 1 );
dt = Open( "$Sample_Data/Big Class.jmp" );
dt<<Graph Builder(
	Size( 518, 448 ),
	Show Control Panel( 0 ),
	Variables( X( :weight ), Y( :height ) ),
	Elements( Points( X, Y, Legend( 3 ) ), Smoother( X, Y, Legend( 4 ) ) ),
	SendToReport(
		Dispatch( {}, "X title", TextEditBox, {Set Text( "weight (ẇ)" )} ),
		Dispatch( {}, "Y title", TextEditBox, {Set Text( "height (ḣ)" )} )
	)
);
I used this site to get the characters: https://graphemica.com/ I then copy and pasted them into the graph.  Does this help?