Blender strategy selection box 2.49b

Hello guys, I was just playing Supreme Commander 2 and I wanted to make my own RTS (Real Time Strategy) game but I’m not very good in “Python” (Python 2.6.2 Blender 2.49b). So i wanted to make a RTS but i cant make the “Selection box”. So if you could, please type the script in the comments. Thanks!