Serial Programming - reset Arduino

is there a simple way to reset the arduino from the serial port ?

Opening or closing the serial port resets the Arduino, unless it has been modified to not reset under those circumstances. If that is the case, then, no the Arduino can not be reset from the serial port.

is there a simple way to reset the arduino from the serial port ?

I think toggling of the DTR serial line causes the arduino to reset. This happens when the standard comport is opened. If you pc program has control of the DTR line, then you should be able to toggle the line within your program.