use CAM::PDF;
    
my $page_number = 1; # Auf Seite 1 stehen alle Infos

my $pdf = CAM::PDF->new('test1.pdf');
my $text = $pdf->getPageText( $page_number );


my ($customer_nr) = $text =~ /Ein Regulaerer Ausdruck zum Matchen der KNR/;

print $customer_nr;