use Data::Dumper;

my @keys = qw( this that those );
my $node = \\my %hash;

# edit:  this was my old way...
# my $i = 0;
# $node = \$$node->{$keys[$i++]} while $i < @keys;

# thanks to Juerd
$node = \$$node->{$_} for @keys;

$$node = "value";

print Dumper \%hash;