multi sub infix:<at> ($dsc, Code $deref) {
  $deref($dsc);
}

my %data = ( foo => [ { quux => 3 }, { bar => { baz => [ 1, 2, 3, 4 ] 
+}, }, ], );

my $dereferencer = { .<foo>[1]<bar><baz>[3] };

say %data at $dereferencer;
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Works in Pugs. Since there doesn't seem to be any good documentation about macros yet, I don't know how to beautify the dereferencer construction syntax, but it ought to be trivial to make a macro that translates deref <foo><bar><baz>[1] to { .<foo><bar><baz>[1] }.

UPDATE: Fixed some blaring typos in the code. Thanks for noting it, blazar. (For some reason, you can't define a Hash in Pugs with

my Hash %foo = (
# something
);
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