Just an idea, but can you pass a command line argument to the msi... then... in the RemoveFiles section, automatically enter the name of the log path and file you have already determined...
So
msiexec /i c:\appname.msi /L*V c:\logfile\install-log.log
You'd add install-log.log as the file to remove.
You couldn't run the .MSI directly, per se, you'd have to store the command line arguments in a .bat or wrap it with SMS installer...or use VB script to execute the MSI with those command line arguments...