A pretty decent start, but what if the number is more then 99? You will need to handle those cases too.
What you said about your ToString() probably won't get you any points as it looks like you're just implicitly calling ToString();
int i=4;
string a=i; //this could be implicitly calling the ToString() function.
I will give you what should probably be a big hint. .ToString() and .Parse() (since you're only doing integers) will be pretty much reverses of thmselves, code-wise.
this is what i came up with if u have some sugestions to make it more efficient they are welcome :P
.toString script
Console.Write("Enter a number as an integer: ");
int input = int.Parse(Console.ReadLine());
string result = null;
do
{
int convnum = input % 10;
input = input / 10;
convnum += 48;
byte ascii = (byte)convnum;
char reschar = (char)ascii;
result = reschar + result;
}
while (input != 0);
char quote = '"';
Console.Write("\nThe result as string is: " + quote + result + quote);
Console.ReadKey();