my @subs = qw(itchy.foo scratchy.bar homer.bab);

open(FH, "template") or die;

my @tmpl = <FH>;

close(FH);

for my $i(@subs) {
  open(FH,">virt.$i") or die;
  for my $j(@templ) {
    $j =~ s/^(\w+)\@DOMAIN$/$1\@$i/;
    print FH $j;
  }
  close(FH)
}