SHARED DOMAIN

Good evening to all. Sorry for the stupid question, but I need help with setup EHCP and how to set up a shared domain for all klienty.Toto is my biggest problem. I need to share about 10 domains. Example: w14.cz, w15.cz, .... Then, each user it will create your subdomain as you need. I am a beginner and this system I really like. Thank you all for your advice.