while (<FH>)
{
  print C $_ if /^abcde.*PARTNAME$/;
}

##</code><code>##

my $re = qr/^$start.*$end$/;
while (<FH>)
{
  print C $_ if m/$re/;
}

##</code><code>##

my $startre = qr/^$start/;
my $endre   = qr/$end$/;
while (<FH>)
{
  print C $_ if m/$startre/ and m/$endre/;
}