To find your fuel filter, you'll need to consult your owner's manual or a repair manual specific to your 2003 Dodge's make and model (e.g., 2003 Dodge Ram 1500, 2003 Dodge Caravan, 2003 Dodge Neon). These manuals will have diagrams and instructions showing the filter's exact location.
Without knowing the specific model, it's impossible to give you a precise answer.