title: how to add content for each line on certain character with powershell
body: <p>I want to add <code>:</code> on text files on certain number of characters for example: </p>
  
  <p><strong>Original text file</strong></p>
  
  <pre><code>ASDWEQRWEASDKLOEWQPEWQLJKEWQ
  QWEKFKLWEJKJSDFJLKSADJAKLSJASDLAKJS
  QWEJKLJSMCJSDJAIQEWJKLASDJA
  </code></pre>
  
  <p>Output file with add content of <code>:</code> on second and tenth position (character)</p>
  
  <pre><code>AS:DWEQRWEA:SDKLOEWQPEWQLJKEWQ
  QW:EKFKLWEJ:KJSDFJLKSADJAKLSJASDLAKJS
  QW:EJKLJSMC:JSDJAIQEWJKLASDJA
  </code></pre>