Minimal Visual Studio project with custom target only: Disable IntelliSense and allow single file processing?

For our Visual Studio Solution, I want to create one project that just generates some files with custom scripts. I have a somewhat-working solution, further reduced to provide as an example here:

This is my minimal.vcxproj:

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
    <ProjectConfiguration Include="Universal|Win32">
      <Configuration>Universal</Configuration>
      <Platform>Win32</Platform>
    </ProjectConfiguration>
  </ItemGroup>
  <ItemGroup>
    <None Include="common.fooconf" />
  </ItemGroup>
  <ItemGroup>
    <Foo Include="file1.foo" />
    <Foo Include="file2.foo" />
  </ItemGroup>
  <Target Name="Build" Inputs="common.fooconf;@(Foo)" Outputs="Output\%(Foo.Filename).bar">
    <MakeDir Directories="Output" />
    <Exec Command='TYPE "common.fooconf" "%(Foo.FullPath)" > "Output\%(Foo.Filename).bar"' />
  </Target>
  <Target Name="Clean">
    <RemoveDir Directories="Output" />
  </Target>
  <Target Name="Rebuild" DependsOnTargets="Clean;Build" />
</Project>

And I need this minimal.vcxproj.filters to make the three contained files show up in VS's solution explorer:

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup>
    <None Include="common.fooconf"/>
  </ItemGroup>
  <ItemGroup>
    <Foo Include="file1.foo"/>
    <Foo Include="file2.foo"/>
  </ItemGroup>
</Project>

Now there are still two problems:

• When loading the project, I get error : Designtime build failed for project '[...]\minimal.vcxproj' configuration 'Universal|Win32'. IntelliSense might be unavailable. Check *.designtime.log files in your %TEMP% directory. If I look up in the log, the error is error MSB4057: The target "GetClCommandLines" does not exist in the project. Of course IntelliSense doesn't make sense here (TYPE is just a placeholder for a custom script), but there must be a way of getting rid of this warning.

• Build (e.g. via F7) works like a charm (even incremental), but it would be really important for us to trigger processing single files (e.g. CtrlF7). But I can't find out how to make this work.