C++ :: String Comparison - Case Insensitive Program

So I have started this program for class but am stuck on what to do next. Basically you need to create a function to compare 2 strings (case-insensitive). The strings shouldn't be altered and the return value should be similar to strcmp.

This is my main file

#include <iostream>
//#include <cstring>
#include <iomanip>
#include "rpstrings.h"
using namespace std;
int main () {
char Str1[20], Str2[20];
short result;

[Code] .....

I don't know if I labeled the files correct. what I need to do is to add 2 defaulted arguments which will allow the user to request that you skip spaces and/or skip punctuation when doing the comparison.

Also, how I can sort the numbers when they aren't justified with leading 0's and if they aren't in the lead string (kinda of like the natural sort).