title: How to replace a character at a certain index with a regular expression
body: <p>Hi i a have string like this one</p>
  
  <p><code>My home is a nice home in Paris but i will go to the home of some one else.</code></p>
  
  <p>i want to replace the character i starting from index 5 to index 25 of the string with the charater Z with a regular expression.</p>
  
  <p>so the result should be </p>
  
  <p><code>"My home Zs a nZce home Zn Paris but i will go to the home of some one else."</code></p>
  
  <p>can you help me please?</p>
  
  <p>i'll use it in java application
  i must create a webservice receiving the regular expression,the string,the begining index, the ending index and it must return the modifed string.</p>
  
  <p>Thank you verry much.</p>