There is probably a clever way to do it with grep and Range Operators, but here is a way using state variables. You should change the flags to more meaningful names for your application: 
use strict;
use warnings;

my $flag1 = 0;
my $flag2 = 0;
my @lines;
while (<DATA>) {
    $flag2 = 1 if $flag1 and /A1/;
    $flag1 = 1 if /SUBSCRIBER/;
    push @lines, $_ if $flag1;
    if (/NATIONAL/) {
        print @lines if $flag2;
        $flag1 = 0;
        $flag2 = 0;
        @lines = ();
    }
}

__DATA__
foo
bar
SUBSCRIBER
goo
hoo
nada
NATIONAL

SUBSCRIBER
goo
A1
NATIONAL
junk
junk
junk

[download]
Prints: 
SUBSCRIBER
goo
A1
NATIONAL

[download]

Update: Ok, here's my solution with Range Operators: 

use strict;
use warnings;

my $flag = 0;
my @lines;
while (<DATA>) {
    if (/SUBSCRIBER/ .. /NATIONAL/) {
        push @lines, $_;
        $flag = 1 if /A1/;
        if (/NATIONAL/) {
            print @lines if $flag; 
            $flag = 0;
            @lines = ();
        }
    }
}

[download]

In reply to Re: Text Extraction by toolic
in thread Text Extraction by JonDepp

Title:
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