title: Replace a character only in the start of a string
body: <p>I want to replace a character <code>":"</code> with a space <code>" "</code> character only in the beginning of a string, if the <code>":"</code> character is present in the beginning. The <code>TrimStart(":".ToCharArray())</code> removes the character not replaces it. And <code>Replace(":", " ")</code> replaces all the occurrences of the character even if they are not in start. What is the solution? Can Regex be used for it? Or any other way? The desired result is:</p>
  
  <pre><code>:abc -&gt; abc
  abc  -&gt; abc
  a:bc -&gt; a:bc
  abc: -&gt; abc:
  </code></pre>