#! perl -sw
use strict;

sub setmode ($\@) { ## the prototype makes the reference
	our @array;                ## satisfy strict
    my $val = shift;
    local *array = shift;      ## alias the reference 
    splice @array, 1, 0, $val; ## do normal array operations
}

my @a = qw( one two three );

print join( "\n", @a ), "\n__________\n";
setmode 'add_test', @a;
print join( "\n", @a );

__END__
[ 7:19:41.56] P:\test>junk3
one
two
three
__________
one
add_test
two
three