I have a generic configuration in an Excel-file, and move it to several hashes by creating the commands as strings and eval-ing them.

As others have mentioned, stringy eval is often not a good idea. Especially when working with hashes, what's wrong with the following?

our %items;
my $item = '3';
my $key = 'Value';
my $value = 2;
$items{$item}{$key} = $value;
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