As long as you can code the logic, you can sort by anything. See sort and How do I sort an array by (anything)?. If these sources are unclear, provide a list of inputs, a desired output order and possibly a rough sketch of your sorting logic so we can provide more guidance (see How do I post a question effectively?). If you specifically want to float a given value to the top of a list (that's the only logical conclusion I can draw from your post), you might use something like:

use strict;
use warnings;

my @not_sorted = qw(you hew dew slew);

my $value = "dew";
my @sorted = sort {
        ($a eq $value) ? ($b eq $value) ? 0 : -1 :
                         ($b eq $value) ? 1 :  0;
    } @not_sorted;
print join "\n", @sorted;
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