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

my %hoh; 

$hoh{'A'}{1}=100;
$hoh{'A'}{2}=200;
$hoh{'A'}{3}=300;
$hoh{'A'}{4}=400;
$hoh{'B'}{10}=500;
$hoh{'B'}{20}=600;
$hoh{'B'}{30}=700;
$hoh{'B'}{40}=800;

rutine(\%{$hoh{'A'}}):


sub rutine
{
	my ($hoh_slice_ref)=@_;

	...
}