CCNet - Delete working copy before MSBuild?

I'm setting up a continuous integration environment, using VisualSVN Server and CrusieControl.NET. What I want to do is delete the working copy before the MSBuild task starts?

I have read that I could use Nant or a Batch file which ccnet would invoke. What is best practice here? Any help on this would me great!

here is an extract of the section of ccnet.config

      <tasks>
        <msbuild>
            <ItemGroup>
                <FilesToDelete Include="C:\CruiseControl\Working\\\**\*"/>
            </ItemGroup>
            <Target Name="Task" DependsOn="Preparation">
                  build
            </Target>
            <Target Name="Preparation">
                  <Delete Files="@(FilesToDelete)" />
            </Target-->
            <executable>                                                      
                C:\WINDOWS\microsoft.net\Framework64\v3.5\MSBuild.exe                                              
            </executable> 
            <projectFile>Example.sln</projectFile>  
            <buildArgs>
                /p:Configuration=Release /p:MSBuildExtensionsPath=C:\Progra~2\MSBuild /p:MSBuildEmitSolution=1 /verbosity:minimal
            </buildArgs>                                                      
            <logger>
                C:\Program Files (x86)\CruiseControl.NET\server\ThoughtWorks.CruiseControl.MSBuild.dll
            </logger>
        </msbuild>
      </tasks>

I have found the answer to my original question:

I simply had to put the cleanCopy true inside the sourcecontrol block.

<sourcecontrol type="svn">                                            
    <trunkUrl>TRUNK-URL</trunkUrl>                
    <executable>SVN.EXE</executable>           
    <username>TEST</username>                                         
    <password>TEST</password> 
    <cleanCopy>true</cleanCopy>         
  </sourcecontrol>