title: Padding zeros with FileHelpers
body: <p>I am using FileHelpers to create NACHA files. Example below</p>
  
  <p>Many of the properties are numeric with leading zeros so they have been defined as strings.  Is there an attribute that can pad the leading zeros in the Class property, similar to the way <code>FieldTrim/TrimMode</code> works to remove whitespace?</p>
  
  <pre><code>[FixedLengthRecord()]
  public class FileControlRecord
  {
      [FieldFixedLength(1)]
      public int RecordTypeCode = 9; //Constant
  
      [FieldFixedLength(6)]
      public string BatchCount; //Numeric
  
      [FieldFixedLength(6)]
      public string BlockCount; //Numeric
  
      [FieldFixedLength(8)]
      public string EntryAddendaCount; //Numeric
  
      [FieldFixedLength(10)]
      public string EntryHash; //Numeric
  
      [FieldFixedLength(12)]
      public string TotalDebit; //$$$$$$$$$$cc
  
      [FieldFixedLength(12)]
      public string TotalCredit; //$$$$$$$$$$cc
  
      [FieldFixedLength(39)]
      [FieldNotInFile]
      public string RESERVED; //Blank
  }
  </code></pre>