It worked. thanks for precise instruction.
By the way, any advise on my second concern: repeated below for your conveinience:
using 1 box 1 eth nic on ADSL @home with dynamic Public IP from ISP provider. With/without ISPConfig, already have Apache/Cemtos page at localhost. Will ISPConfig manage the IP change automatically. Intent to use free external DNS provider such as everydns or editdns, can ISPConfig manage this arrangement? do I remove BIND? Maybe should start another thread, but I need to know in principle if I will hit a wall after going thru this BS bump, so I can abadon this project and try another, maybe Virtualmin