If you want to reverse the letter order in a word, you can do that by splitting the word into characters (via split), and then rejoin them in the correct order:
# Take a word
my $word = "Constantinople";
# Split into letters:
my @letters = split '', $word;
# Reverse them
my @srettel = reverse @letters;
# Join back into a single word:
my $drow = join('', @srettel);
Of course, you can combine it all into a single step:
my $drow = join('', reverse split //, "Constantinople");
Update: Or you could (as johngg pointed out) just use reverse, and it'll do the job without all the hoop-jumping-through-stuff.
When your only tool is a hammer, all problems look like your thumb.