Depends what you mean by metallic - do you mean that the subject itself looks metallic or that the print has that glow to it? For the former case, lighting is key. You want a glossy subject that is specularly-reflecting a large white field, for example I recently found that wet rocks reflecting a cloudy sky look extremely metallic when printed on Ilford RC Pearl.

You can also buy metallic RA4 paper that has a load of fine silvery metal balls between the paper and the emulsion; I think it's called Kodak Pro Endura Metallic. I've had digital prints (no reason you couldn't do it from a scan) made on it with a lightjet and it works extremely well with subjects that contain a lot of saturated colour but it has poor dynamic range. You will lose a lot of both highlight and shadow detail compared to a normal RA4 paper. When a colourful print on this stuff is directly lit, the print has a beautiful glowing backlit appearance to it.