Get a shop manual with wiring drawings. Compare USA vs. Canada where DRLs are required. It might not be easy...

My '95 Integra had 1 relay & 1 resistor pack to plug in, to 'install' DRLs.

My '98 Accord Helm manual shows some major changes in wiring harnesses between USA vs. Canada. So I bet the '03 would not be as simple as plugging in a relay. (I don't have the Helm book yet.)

Besides, Honda DRLs traditionally use the low-beam bulb at reduced voltage, not the highbeam. So you'll have to design your own circuit.