Gcode addition post processing of K2 model file

I would like to add gcode to achieve , after printing successfully, to continue the build plate temperature @62 deg and the chamber heater continue staying active @55deg.
Both parameters would stay live for 5 Hours after print.

Not sure if I have to modify the gcode within gcode_macro.cfg or I could add to the post processing within the appropriate model file. Appreciate any help in this direction.

Have never coded machine gcode and am studying various klipper gcode pages in the hope of achieving the above.

@Bill.b Saw you posted some nice code (which I understood) but need to understand where to action after the finishing of the printing.

Obviously I can just go to the dashboard and set it, but would love to be able to automate such.

Cheers All