What is the easy way to read the com serial port?

Hello

im trying to read the serial port using autoit.
I have a old PDA, and i want do something like this: http://kr3l.wordpress.com/2008/12/07/serial-com-port-communication-with-autoit/

So the autoIt read serial port and just waits for characters to be sent. If one of the characters U,D,L,R or C is sent, autoIt will emulate a keypress of one of the Media functions.

Unfortable the code in this blog doesnt work. Can somewone help me with a help to fix the code in this blog, or help me with a way for i can read the serial port (?without ddls?)