You might have to do something like this as you don't have too much control on the powerpoint layout (use images to workaround some of the issues)
Names Default To Here(1);
dt = open("$SAMPLE_DATA/Big Class.jmp");
gb_expr = Expr(dt << Graph Builder(
Variables(X(:weight), Y(:height), Overlay(:sex)),
Elements(Points(X, Y, Legend(9)), Line Of Fit(X, Y, Legend(11)))
));
rep = V List Box(Align("right"),
H List Box(align("center"),
Text Box("Title of presentation", << Set Font Size(50)), Icon Box("JMPLogo")
),
gb_expr
);
vlb = V List Box(rep << get picture);
vlb << journal;
//Try(Delete File("$TEMP/saveppt.pptx"));
Current Journal() << Save Presentation("$TEMP/saveppt.pptx", Outline Titles("BottomRight"), "PNG");
Or you could write python script and call that from JMP to create the powerpoint (provide it with images and maybe text from JMP).
-Jarmo