I've never done a rolled neck in crochet, but I have in sewing and knitting. In general, a rolled neck is just extra rows of a non-ribbed stitch or fabric that will roll. If you take a standard neck pattern and just do it in a stitch that doesn't have sufficient body to not-roll until it rolls as you like it. You may have to use more or fewer stitches to get the right size if the stitch you use is a different size than the original stitch.
Hope that helps,
Julie