first think u need nameserver ex: ns1.domain.com ( you can set it in your domain registrar company ) second dns manager on your windows 2012 , setup dns service and set your ns1.domain.com on your local IP 192.168.1.103 . next add A record to * and Empty and www to localIP 192.168.1.103 , now dns is oky
next go to iis and add bind domain.com to your website under your iis
don't forget add portforwarding 53 in your modem adsl to your localip port 53.
all is done and enjoy your home host company