exclude projects while building a visual studio solution from batch file script

Question

I have batch file to build a .NET solution like below:

<MSBuild Projects="$(BuildDirectoryPath)\$(TrunkBuildDirectoryName)\Core\Core.sln" Properties="Configuration=Debug"   Targets="Clean;Build" />
<MSBuild Projects="$(BuildDirectoryPath)\$(TrunkBuildDirectoryName)\ExternalSystems\ExternalSystems.sln" Properties="Configuration=Debug"   Targets="Clean;Build" />
<MSBuild Projects="$(BuildDirectoryPath)\$(TrunkBuildDirectoryName)\MDMAPI\MDMAPI.sln" Properties="Configuration=Debug"   Targets="Clean;Build" />

How do I exclude some projects and folders while building a visual studio solution from batch file script?