nearest approach would be that of fixing a translucent paper onto the glass from behind, and attaching a gnomon using silicone caulk on the front.
One could plot the sundial onto tracing paper, or else paint the sundial onto so-called 'satin' glass which is translucent and matt from one side, and shine and 'glassy' from the other side.
Regards Alexei Pace Malta 35degs50N 14degs33E -
