import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class ReplaceExample {
public static void main(String args[]) {
String regex = "(\\w)(\\d)(\\w+)";
Pattern pattern = Pattern.compile(regex);
String candidate = "X99SuperJava";
Matcher matcher = pattern.matcher(candidate);
String tmp = matcher.replaceAll("$33");
System.out.println("REPLACEMENT: " + tmp);
System.out.println("ORIGINAL: " + candidate);
}
}