You can use scriptXSI.bat in %XSI_HOME%\Application\bin to create a desktop shortcut for batch rendering. When you drag and drop a scene file on that batch file, that starts a batch render.

To create a desktop shortcut, right-click scriptXSI.bat and click Send To > Desktop (create shortcut).

If you want to drag and drop multiple scenes:

1. Copy scriptXSI.bat to your desktop.
2. Edit the batch file and change it to this:

   @echo off
   call "C:\Program Files\Autodesk\Softimage 2011 Subscription Advantage Pack\Application\bin\setenv.bat"
   :next
   if "%1"=="" goto end
   set SCN=%1
   "C:\Program Files\Autodesk\Softimage 2011 Subscription Advantage Pack\Application\bin\XSIBatch.exe" -render %SCN%
   shift
   goto next
   :end