title: How to insert a dot between a string
body: <p>Hello every technical elite, I'm a rookie in C#. This is my first time asking questions on stackoverflow, I'm a Chinese, my english is poor.</p>
  
  <p>I am trying to make my C# application communicate with a digital scale via rs232 by using SerialPort class in .net.</p>
  
  <p>I want insert a dot "."  in a string ,I received the string use:(buf[3].ToString("X2"),the string is a number between 00~99,I  want insert a dot in the number.How to do ?</p>
  
  <p>Thanks a lot for any help.</p>