FileLogTraceListener format timestamp

I m using system.diagnostic tracing, to log info. Somehow it logs the time like this:
2011-09-06 04:52:07Z      1247117878029

What i want something likes this: 2011-09-06 04:52:25,323 (in milliseconds)
How to do that to format to milliseconds? here is the config:

      <add name="SampleTrace"
           type="Microsoft.VisualBasic.Logging.FileLogTraceListener, Microsoft.VisualBasic, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"
           logFileCreationSchedule="Daily"
           traceOutputOptions="DateTime, Timestamp" />


      <source name="Test.Config" switchName="Config" switchType="System.Diagnostics.SourceSwitch" >
        <listeners>
          <add name="SampleTrace" />
        </listeners>
      </source>