set($ref_to_hash,1,(a c b d))

# set($hoh,$val, @path): ... by ariels

sub set {
  my $hoh = shift;
  my $val = shift;
  my $last = pop @_;
  $hoh = $hoh->{$_} for (@_);
  $hoh->{$last} = $val
}

##</code><code>##

#create first node
$hr=\%I;
$hr->{'one'}=1;

#create tmp node and link back in
$new=\%tmp;
$new->{'two'}=1;
$hr->{'one'}=$new;