How to make a block's texture be 2d and follow the player like a barrier block?

so I'm making a mod which adds the beta sm64 coin and star as a little unofficial extension to the "super mario 64 in minecraft" mod, but I don't know how to make the textures act like the barrier block's texture. I don't want to make them have a cross model, I want to make them act like how they would have acted in the original game - billboard textures basically.

does anyone know how to do this? any help would be greatly appreciated!