Quote from ORelio
There isn't any simple way to do this, because the modded server requires the client to be modded as well. This means that for each mod, Minecraft Console Client should be able to mimic the mod's behaviour.
I would have assumed that for the already setup packets (ie those already labelled by Mojang), it would have been the same protocol. In which case it should already work.
PS I cannot test these claims, I have a Mac.