Baby cowries have a free-floating veliger stage, so it is unlikely that any of the babies will survive; powerheads, skimmers etc. will kill them and corals will eat them. If you move the eggs to a separate tank with an airstone for circulation they may have a chance. I have no idea what the veligers eat, maybe phytoplankton?
If you are going to try to hatch them document everything because it's never been done successfully before to my knowledge.