title: Use regular expression to replace character in specific position
body: <p>I want to replace the dash(-) to space from a string at position 12.
  I cannot use replace(&quot;-&quot;,&quot; &quot;) because there may a negative number in the string.</p>
  <p>I had try (?&lt;=^(?:.{11})).  but it only get the result at first line.</p>
  <p>Are there any solution?</p>
  <pre><code> K120613763-01       1100625     TL             -11,008                 0           -11,008                                                                                        
   N123203270-02       1101024     PWL               -387                 0              -387                                                                                        
   I200543078-01       1101029     PDDW              -311                 0              -311                                                                                        
   A122285277-03       1101101     PWL                530                 0               530                                                                                      
   A127477426-03       1101101     PWL                458                 0               458                                                                                      
  </code></pre>
  <p>I want the result like below.</p>
  <pre><code> K120613763 01       1100625     TL             -11,008                 0           -11,008                                                                                        
   N123203270 02       1101024     PWL               -387                 0              -387                                                                                        
   I200543078 01       1101029     PDDW              -311                 0              -311                                                                                        
   A122285277 03       1101101     PWL                530                 0               530                                                                                      
   A127477426 03       1101101     PWL                458                 0               458                                                                                      
  </code></pre>
  <p>Note: Lines start with a space</p>
  <p>I use vb.net to programming in uipath.</p>
  <p>I tried this but it doesn't work:</p>
  <pre><code>System.Text.RegularExpressions.Regex.Replace(strTxt, &quot;/(?&lt;=^(?:.{11}))./gm&quot;,&quot; &quot;)
  </code></pre>