Re: How Can I Convert new Pantone metallic Color to CMYK?
First, is your proofer calibrated and profiled to match your press sheet? If not, that's the first step.
Other than that, I would use Relative Colorimetric Intent (the default) to come up with a color match. Unfortunately, for metallics, the outcome doesn't look very good. If you have a calibrated and profiled monitor, you can come up with your own CMYK values that most closely match the metallic color. For instance, I know 877 silver shouldn't be near as dark as what color management makes it (rings true for all metallics that I've seen). So what I can do is make a Photoshop Lab document, fill it with Lab values of the metallic color, make a duplicate, and (making sure the CMYK profile in color settings describes your press output) convert to CMYK. Then use curves to tweak the CMYK one to match the Lab one in appearance.
Don