title: VS platform toolset on the command-line, for use with make-files
body: <p>I have a portable CLI tool that builds on the command-line using a simple make-file. I have adapted the make-file so it builds using NMake and the VC++ command-line tools, but I can't figure out how to request the "vs120_xp" toolset.</p>
  
  <p>I'm aware I can set the "vs120_xp" toolset for a new VS project and build inside the IDE or using MSBuild on the command-line, and it works fine, but I want to avoid converting my whole make-file if possible.</p>
  
  <p>Is there any argument I can pass to the "vcvarsall.bat" or "vcvars32.bat" scripts, some arguments to NMake, some pre-processor definitions in the make-file, or some global settings somewhere, that I can use to control this?</p>