How to define the interrupt function ( UART0 )

hi
i whant define function "UART0_IRQHandler" in my library ( uart library )
but i dont whant use
#include <lpc17xx.h>
and
startup_LPC17xx.s

I tried this code but did not work
void (*test) (void) = (void (*) (void)) 0x54;

in file "LPC176x/5x User manual ( UM10360 )" and "Table 50" :

Interrupt_ID : 5
Exception_Number : 21
Vector_Offset : 0x54
Function : UART0
Flag(s) : Rx Line Status (RLS) Transmit Holding Register Empty (THRE) Rx Data Available (RDA) Character Time-out Indicator (CTI) End of Auto-Baud (ABEO) Auto-Baud Time-Out (ABTO)