#pseudo code
struct SubFields => {
   Description => '$',
   Date => '$',
};

my $s = XML::Simple->new;
my $tree = $s->XMLin($someFile);
my $subfields = SubFields->new();

$subfields->Description ( $tree->{ImportantStuff}->{VeryImportantStuff}->{Item1}->{Description} );

print Dumper($subfields);
print Dumper($tree);