Syntax: IPAddr = LookUp ( AddrString
||The first IP address found by the DNS lookup
||A domain name or dotted address string
This method converts an IP address from string to numeric format.
If AddrString is a dotted numeric address such as "127.0.0.1",
does the conversion and returns immediately.
If AddrString is a domain name, LookUp does a DNS lookup and
returns the first IP address found. If the lookup fails, LookUp returns 0
and sets the Error property.