my @A = (1,2,3,4,5,7,21,55,66);

sub TIEARRAY {bless [@_[1..3]],$_[0]}    
sub FETCH {$_[0][0][$_[1]+$_[0][1]]}      

tie my @B, "main", \@A, 2, 4;

say $B[0];
say $B[1];
say $B[2];

__END__
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