write Functions at specific locations

Hi All,

I am trying to write functions at specific locations.
I am using KEIL 4 IDE ... and LPC2478
Though I could find a keyword "FIXED" which says one can write function at specific locations, but don't know how to use it .

This is what I want to achieve ....

for eg :

void main(void){
function_1();
function_2();

}

void function_1(){

}

void function_2(){

}

I need "function_1()" to be placed at specific location ...say...address 0x2000.

and

I need "function_2()" to be placed at specific location ...say...address 0x4000.

Can this be achieved ....and if yes How can I do this ?

All suggestions are welcome....
(I could not understand how the keyword "FIXED" works )....

Thanks ...
K.Ganesh