In this case you just need to put the reference information in a hash from the reference file and use that for look up instead of an array. A hash has the syntax

my %hashname = (); # init empty hash
$hashname{key1} = "value1";
$hashname{key2} = { x => 'y' }; # nests an anonymous hash as the value
+ for key2
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often you want to store a hash reference in a scalar to avoid referring to the entire hash, e.g. :-

my $href = \%hash;
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hope this helps