some nuget packaging adjustments
diff --git a/src/csharp/build_packages.bat b/src/csharp/build_packages.bat
index fab80b0..fe7e0a4 100644
--- a/src/csharp/build_packages.bat
+++ b/src/csharp/build_packages.bat
@@ -1,10 +1,16 @@
-@rem Builds NuGet packages
+@rem Builds gRPC NuGet packages
@rem Adjust the location of nuget.exe
set NUGET=C:\nuget\nuget.exe
+setlocal
+cd ..\..\vsprojects\nuget_package
+@call buildall.bat || goto :error
+endlocal
+
@call buildall.bat || goto :error
+%NUGET% pack ..\..\vsprojects\nuget_package\grpc.native.csharp_ext.nuspec || goto :error
%NUGET% pack Grpc.Core\Grpc.Core.nuspec || goto :error
%NUGET% pack Grpc.Auth\Grpc.Auth.nuspec || goto :error
%NUGET% pack Grpc.nuspec || goto :error