You can cut flat numbers the size you need from gumpaste or fondant. Attach wire to the back (for insertion into the cake) and coat the front in disco dust/edible glitter to give it the sparkle you were looking for? Or you can do what I see many people do and roll out a “log” of fondant or gumpaste, curl into the number shapes you desire and insert a wire into the bottom for insertion into the cake.

Thanks for your idea…i ll trying the firts options. Thanks