Software Deployment

i need to write to two seperate log files in my installation using Installshield 2012 Premier Enterprise,  A single setup.exe is my companys standard deployment, i cant change this, its just what they do. The company used to use Wise to do this but has moved on to AdminStudio. So i take a msi and wrap it up in a single Setup.exe.

I can write to one log file by using /qnlv "c:\logs\nameofpackage.log" in editor under Media/Releases/stup.exe tab/MSI Command Line Arguments. its a nice simple verbose log file, the second log file needs to write to an existing log file that i need to append to when the installation starts, and when the installation ends, something like   %computername% %username% %date% %time% Installation Started  >> c:\utils\logs\log.txt, and then another similar line for when the installation ends. i cant find anything on doing multiple log files, any ideas?