Lpc2000

i'm new in programming µc but i have some skills in c programming. 
i read in the user manual of the lpc 2124 all about the vic how to 
set the variables. but i do not understand how and where i can 
programm my fiq- or irq-isr in c-code. for the irq-interrupts there 
are the addressregisters, but not for the fiq. so where does it jump? 
how can i programm in c that here is the start-address and the 
interrupt jumps in this function?  

isn't it possible?
i only found some examples here in assembler, but i do not understand 
it.  

thx

andreas