title: replace characters in string before file extension
body: <p>I've got a variable, with the following string values:</p>
  
  <pre><code>PS C:\&gt; $sql.physicalname
  I:\Data\Data1.mdf
  I:\Data\Data2.ndf
  I:\Data\Data3.ndf
  I:\Data\Data4.ndf
  I:\Data\Data5.ndf
  I:\Data\Data6.ndf
  I:\Data\Data7.ndf
  I:\Data\Data8.ndf
  I:\Data\Data9.ndf
  I:\Data\log.ldf
  </code></pre>
  
  <p>What I want is to replace/trim the strings so that only the .mdf/.ndf/.ldf extensions remain:</p>
  
  <pre><code>.mdf
  .ndf
  .ndf
  .ndf
  .ndf
  .ndf
  .ndf
  .ndf
  .ndf
  .ldf
  </code></pre>
  
  <p>I tried using the <code>-replace</code> parameter with the <code>*</code> wildcard, but I cant wrap my head around it.</p>