Business Edition of 4.x and Batch Files

We are using the installation method where we place a config XML file in the folder where the MSI file resides for installations and calling the MSI directly (it's easier with our remote facilities where the VPN's are slow) ... in any event, I wrote a simple batch script to allow the user to specify the source drive and select the version (32 or 64 bit) to install ... works great.

Recently we had some issues where it would statr to install then fail with no error. I added logging (/LVX* <log file name>) which is nice, buT i wanted to addd some feedback to the batch file for error levels ... can't find any information on this; anyone know what they are or where I can find them?