Padding zeros with FileHelpers

I am using FileHelpers to create NACHA files. Example below

Many of the properties are numeric with leading zeros, so they were defined as strings. Is there an attribute that can put leading zeros on the Class property, similar to how it FieldTrim/TrimMode

works to remove spaces?

[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
}