how to use multiple loops

Hi, i have a question.
I’m using this script

<div>
<?php
$sticky=get_option('sticky_posts');
$args=array( 'cat'=>20, 'caller_get_posts'=>1, 'post__not_in' => $sticky, 'posts_per_page' => 4 );
query_posts($args);
?>
<?php $c = 0; ?>
<?php while (have_posts()) : the_post(); ?>
<?php include (TEMPLATEPATH . '/index.php'); ?>
<?php endwhile; ?>
<?php unset ($c); ?>
<?php  wp_reset_query(); ?>
</div>

<div>
<?php
$sticky=get_option('sticky_posts');
$args=array( 'cat'=>3, 'caller_get_posts'=>1, 'post__not_in' => $sticky, 'posts_per_page' => 4 );
query_posts($args);
?>
<?php $c = 0; ?>
<?php while (have_posts()) : the_post(); ?>
<?php include (TEMPLATEPATH . '/index2.php'); ?>
<?php endwhile; ?>
<?php unset ($c); ?>
<?php  wp_reset_query(); ?>
</div>

two different loops to choose category 3 and category 20 posts excluding sticky post. I’m trying to change this by using one loop, something like

<div>
<?php
$sticky=get_option('sticky_posts');
$test=array('3','20');
$args=array( 'cat'=>$test, 'caller_get_posts'=>1, 'post__not_in' => $sticky, 'posts_per_page' => 4 );
query_posts($args);
?>
<?php $c = 0; ?>
<?php while (have_posts()) : the_post(); ?>
<?php if ( in_category('3') )  { include 'index.php'; } ?>
<?php elseif ( in_category('20') )  { include 'index2.php'; } ?>
<?php } else { } ?>
<?php endwhile; ?>
<?php unset ($c); ?>
<?php  wp_reset_query(); ?>
</div>

but obiovusly it doesn’t work. Is possible to do what i need? i’m not a coder i’m trying and trying but….
thanks in advance.