Guess this is something that has been added to the newer models. My 03 can be programmed while driving. I can even program system settings.
In any case, KP Technologies sells several different modules that work with our cars. They also sell Navigation Interface Module. However, it is specified to work on Infinity/Nissan. Here's the kicker though. They use to advertise the NAVI "OK" Bypass module as something for our Accords. Now they don't list it as being compatible. Thing is, I know it is compatible because I have it on mine. I had to hard wire to the circuit board inside the radio, but it does work.
Now this Navigation Interface Module they advertise is to allow you to program the NAVI while the vehicle is in motion (like you are wanting). However, it does this by interrupting the vehicle speed sensor circuit. So if you know what you are doing, it just might be possible to adapt this module to work. It's worth researching.