i don't think that you can, if the dual fuel lanterns are same as the dual fuel stoves then all it really means is petrol or coleman branded petrol, not really dual fuel at all. bio-ethanol is alcohol, more or less the same as meths, i think that it would probably be quite exciting if you tried to run a pressurised petrol burner on alcohol, and not necessarily good exciting either! it may be possible to get some kind of conversion kit/parts to make it work, but i'm not sure, rik or bilmo should pop up at some point to put you right on that bit.
cheers
stuart