This code uses Math::Combinatorics to work out the combinations. It is easier to work out the combinations that you want to keep rather than those that you want to get rid of.

use Math::Combinatorics;

my @cols = (0..12);
my @combin;
my @data = ('A'..'Z');

my $combinations = Math::Combinatorics->new(count => 10, data => [@col
+s]); 

while (@combin = $combinations->next_combination()) {
    print join("\t", @data[@combin]), "\n";
}
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