perhaps a cleaner way to do this, would be to inherit from the existing CaptureWindows class, and move the only part you've changed to a new private method that you override in this class e.g. 

    def capture_command
      Open3.popen3("#{commandcam_exe} /filename `cygpath -w #{snapshot_location}`#{delaycmd}")
    end

Since both implementations are almost the same, with the exception of this call.