Lpc2000

i use in the lpc2124 the pwm to create a 4mhz signal but i also need 
a signal with a frequenzy of the twothousandth part with a pulsewidth 
of 0.05% (like a needle) to reset a cmos-linesensor. so i create 
interrupts of 4mhz and count with an value to 2000. when the value is 
1 i set an i/o pin, if it's 2 i clear it. but it only works with a 
frequenzy up to 0.8mhz, otherwise the interruptroutine is to slow.

so i had an another idea: with timer 0 i create my 4mhz pwm-signal 
and with timer1 and the MRx i want to create the needle-signal. but 
in this case i have to toggle one External Match Output's with two 
different MRx. but i think that is not possible. 

do you have an idea how i can handle it?

thanx