By combining -script and -render, you can use a script to set up a scene for rendering. xsibatch loads the scene, runs the script, and then does the render.
Any changes made by the script are not saved.
You can also use -script with -export flag. For example, if you wanted to change the output folder for .mi files, you could do this:
xsibatch -processing -export \\server\share\xsiDB\Scenes\test.scn
-script tmpChangeOutputDir.js -frames 1-5 -pass all
where the .js file changes Passes.RenderOptions.OutputDir to the desired output location.