How to implement this operation?

scorpiusli

If there is a string: 0301, I want to add 1 to the string to become 03O2. How to achieve this.

scorpiusli

Anxious, please help.

stone86

private string AddNumber (string str)
{
int temp = Convert.ToInt32 (str);
temp + = 1;
string str2 = temp.ToString ();
return str2;
}