The remote and keyless system are already programmed to work the trunk release, your car is just lacking the power trunk latch. You'll want to find a trunk opener kit, it was a dealer installed accessory that replaces the non-power trunk latch with a power operated one.

Here are the instalation instructions, you'll also see the part # at the top of the page: http://www.hondaautomotiveparts.com/.../20032_01.html