Need ceiling fan remote that also uses controls at existing wall switch
I beleive that you can do this using a remote control switch set such as this one



You will need two switches, one for the light and one for the fan. The remote shown has two channels. You need to check that the fan does not exceed the wattage recommended and that the dimming circuit in the switch can handle a motor, not just incandescent lights.

Several manufacturers make these types of devices, so search for ones that meet these criteria. Here is another version