So close, but yet so far . . .

I have been trying to add the aspect ratio function for my Sharp HDTV (LC-37D90U) to my Comcast remote (URC 1067ABC1), but I have been unable to find an EFC that works, despite scouring the web. On another thread ([Link: hifi-remote.com]) that linked to this one, "Richard" said 00154 worked for him (converted from Sharp:17:200 = Aspect Ratio in Keymap Master), but that didn't work for me using the 0093 device code for Sharp or the alternate 0017 device code that worked for Richard. Most of this is over my head. I have tried using Keymap Master and RemoteMaster, but neither seems to have the data files for my remote or TV and trying to download information from my remote is something I would try only as a last resort. Is there some way to use the Hex codes posted here to figure out the correct EFC to change the Sharp aspect ratio with the Comcast remote? Any help would be appreciated.