I don't pretend to know the Socket module and you don't clarify whether you're after "more control" of your socket solely for the purpose of binding to an arbitrary IP, but IO::Socket::INET is quite capable of doing so ...

#!/usr/bin/perl

use IO::Socket;

use constant DEFAULT_SERVER => "whois.networksolutions.com";
use constant DEFAULT_IP     => "0.0.0.0"; # any

sub whois {
   my($domain,$server,$ip) = @_;

   $server ||= DEFAULT_SERVER;
   $ip     ||= DEFAULT_IP;

   my $whois = IO::Socket::INET->new(
                 PeerAddr  => $server,
                 PeerPort  => "whois(43)",
                 Proto     => "tcp",
                 LocalAddr => $ip,
               );
   return unless defined $whois;

   $whois->print( "$domain\r\n" );
   return $whois->getlines;
}

die("Usage: $0 domain [whois server [local ip]]\n") 
  unless @ARGV;

print whois(@ARGV);
[download]

If you still need to use Socket instead of IO::Socket::INET, perhaps a peek under the hood of the latter is in order so you can figure out how the above wraps around the lower level stuff.

    --k.