title: How can i modify part of a row in file?
body: <p>I have a file witch contains multiple rows with strings like this:</p>
  
  <p>DTSTART:20190716T180000</p>
  
  <p>DTEND:20190716T180000</p>
  
  <p>I want to modify every DTEND row. I want to replace the 180000 with 190000.
  The Parts between DTEND: and 180000 are different each time. Does anyone now how I can change the string in powershell?</p>