I read from dpreview forum that the OmniRemote software for Palm organizer can be programmed to do the trick.
I have obtained all the codes for my old idling Palm V. I had setup all the buttons in the same way as Canon WL-DC100.
Will continue to try to test it out after I return to home this evening.
Yes, I downloaded some program before and tried, it worked but the distance is very limited, maybe 1m or 2m. not really useful, and do you really want to bring a pocket pc in your camera bag when going out?