Think of the Windows Task Scheduler, where you can run any kind of executable file, passing parameters and creating dependencies. That's exactly what Supporting Tasks are for. Any thing that is not Reload, Distribution, Reduction, like sending some emails calling to an external program, running a backup after the nightly reload... You can do all that from the Supporting Tasks with the plus that you can make them dependend of your pure QlikView tasks.
For example: run a BAT file to check when a status from a database has ended, then if it went right start a reload, and after that, call to your corporate backup software to store the recently generated QlikView files.
Hope that gives you an idea.
I've created a vbs script file which accesses the QV document data to format a mail body and sends a mail. The vbs works properly wen triggered via command prompt. However i tried to trigger the vbs script via a batch file using a supporting task. Though the supporting task runs successfully, it doesn't trigger the vbs. (I don't receive any mail.) Does supporting task do not support this types of operations?