I refactored the alphabet program so a separate method is easy to copy for other applications. Feel free to use this program, or the separate method; labled 'addOrderAppendage'.

alphabetInNumericOrder.java

import java.util.Scanner;

class Alphabet {
    static String[] fields = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
            "k", "l", "m", "n", "o", "p", "q", "r", "s", "t",
            "u", "v", "w", "x", "y", "z"};
    public static void main(String[] args) {

        String letter = null;
        letter = pickALetter(letter);
        printTheLetter(letter);
    }

    public static String pickALetter(String l)
    {   Scanner in = new Scanner (System.in);
        System.out.print ("Enter a Letter to find out what order it's in: ");
        l = in.next();
        l = l.toLowerCase();
        return l;
    }

    private static void printTheLetter(String letter) {
    for (int i=0; i < fields.length; i++ ) {
        int j = i+1;
        if (letter.equals(fields[i])) {
                System.out.print("The letter " + fields[i] + " is the ");
                System.out.println(+ j + addOrderSuffix(j) + " letter in the alphabet.");
        }
    }
    }

    static String addOrderSuffix(int i) {
        if ((i % 10 == 1) & (i != 11)) {
            return "st";
        }   else if ((i % 10 == 2) & (i != 12)) {
            return "nd";
        }   else if ((i % 10 == 3) & (i != 13)) {
            return "rd";
        }   else {
            return "th";
        }
    }
}