I don't think your system command is correct...
Try using:
system("start C:\\Program Files\\LucasArts\\Star Wars Battlefront II PS2 Server\\data\\_LVL_PC\\COMMON\\ainum.exe");
You don't need to put the path in quotes.
[EDIT]
The start command will run your new program and the source program will continue it's execution.
If you want to wait for your new program to end before continuing the old one then remove the "start" from the beginning of the system() call.