How to save a value into only one excel`s cell ?

Question

Hello:
I  want to write  only a value into one excel`s cell , and save the excel file.
I  want reserve all other cells` values .
I  used NPOI ,it has to read all the value , and save them all into another sheet. It is not i want
How should I do ?
thanks!

Answer 1

            private string Test(byte b)

            {

                  if (b >= 1 && b <= 3)

                  {

                        return "Good enough";

                  }

                  else

                  {

                        return "Out of range";

                  }

            }