MG doesn't use .NET. Windows does require building with Visual Studio, though, which does use .NET (but is really just an indirect requirement).
At any rate, you should be able to modify the batch file to build a specified project inside the solution. The lines you'd want to change are the ones that invoke
msbuild. The
/t:ProjectName argument is what you want (see the
reference here). The batch file appears to be a mess (or at least in the last revision I had checked out -- can't be bothered updating), with commented out lines (starts with
rem). There should be two lines that actually do anything with
msbuild, one that is used if an argument is "rebuild" and another used by default.