If the rest of your file looks the same, you don't even need an index. Each line that you pasted has 34 characters (assuming that the newline is a single line-feed, and not CR LF as on windows), so to get the $n-th line (and you start counting the lines from 0), you can just do
my $bytes_per_line = 34;
my $pos = $line_number * $bytes_per_line;
seek(IN, $pos, 0);
my $line = <IN>;
If you need to access by the first column (and not line number), subtract the value of the first row before calculating the line number.