Stomp the highlights hard with the Highlights & Shadows Brick, then adjust (usually brighten) the overall scene with the Levels Brick central slider (move it leftwards). Adjust to suit. When using the H & L tools, always fine tune using the Width and the Mid-Contrast sliders. Definition, subtly applied with the Quick Brush, will add some sparkle.
Printing snow is hard. First, you need a precisely exposed photograph taken with a camera that has a wide luminance range and that makes this range available to the photographer. There can't be any blown highlights. Then you need excellent white balance. Then you need enough dynamic range to darken the snow enough that details (textures) show in it, while not dimming the overall scene. And then you need a good printer, well calibrated. Be sure to soft-proof your images on-screen.
Keep in mind that our perception of images is always relative: the appearance of brightness is caused by a difference in luminance, not by any absolute luminance.
Message was edited by: Kirby Krieger -- added note re: soft-proofing.