For reasons that I can't explain (other than possible win32 environment variables), I've had to launch window specific files such as .bat, .cmd, and some .exe files like the following:

if($^O=~m/Win32/) {
  $winnt = `echo %SystemRoot%` ;
  chomp($winnt);
}

system ("$winnt\\system32\\cmd.exe","/c [ABSOLUTE_PATH_TO_BAT_CMD_OR_S
+OME_EXE]");
[download]

who know's maybe it holds true for .vbs files.