#!/usr/bin/perl -w
use strict;
use diagnostics;

my %hash = (
	VERTRAG1 => '123',
	VERTRAG2 => '345',
	VERTRAG3 => '678',
	VERTRAG4 => '91011',
	FOO => '91011',
	BAR => '91011',
);

foreach my $temp (sort {substr ($b,7) <=> substr ($a,7)} grep {/^VERTRAG(\d+)$/ && $1 < 3}  keys %hash) {
	print "Untersuche $temp\n";
}