For the 2004 RC you can take a look at:
http://www.ifirobotics.com/docs/lega...2004-02-26.zip
For the default code. To get an analog input from that:
Get_Analog_Input(rc_ana_in01);
That should give you the 10 bit analog value for what ever you have hooked up to analog input 1.
That code should compile straight out of the box (zip) with mplab 7.20 and 2.4 (i think) compiler