write a program in c++ or c# to calculate the contents

As is often suggested you will need to do a little work using Google.
Registers are CPU specific and will you will need to employ CPU instructions directly to read their values. This will require assembly language functions or inlining ASM.

You have not stated CPU or OS so you seem not to have done too much homework yet.

From here I got this example to read Intel EDX:

http://sim0n.wordpress.com/2009/04/15/c-getting-register-values/[^]

#include <iostream>

void setEDX(int value) {
	//Moves 'value' into edx
	_asm mov edx, value;
}

int getEDX() {
	int value;
	//Moves edx into 'value'
	_asm mov value, edx;
	return value;
}

int main()
{
	int edxValue = getEDX() ; //Get Register
	std::cout << "EDX: " << edxValue << "\n"; // Display

	std::cout << "Set EDX Value: ";
	int value;
	std::cin >> value; //Get input
	setEDX(value); //Set register

	edxValue = getEDX() ; //Get Register
	std::cout << "EDX: " << edxValue << "\n"; //Display

	system("pause");
	return 1 ;
}

Work on understanding this example and you will be in business.

Repeat this process for all the CPU registers you wish to examine.

If it is not CPU registers you need but device registers (eg UART) then the same technique can be used.

The problem is not easy to solve and debug, but this is quite doable. The simplest basic idea is to push registers to stack. Then you can modify any registers used to moving data from stack to some memory, for example, representing the location of output parameters in the stack frame or some structure passed by its address. Then you restore the stack or just use it on return. Usually, you don't need to save instruction pointer, as you can use the address of some function of return address.

—SA