I finally figured out how to program the new remote! It turns out that there is precious little information on the comcast website about it - you have to search and search, and then wade through many side-tracked websites before you find the right one - and even it isn't the perfect solution! The 'new' comcast controls are old, discontinued models that are no longer archived on the maker's website - Comcast apparently snapped them up on the cheap. They are good enough remotes, though - no complaints other than there is STILL no eject button for the VCR/DVD. Oh well...
I now have it programmed to control (minimally, in some cases) the Cable box, TV, VCR/DVD combo unit, and Dolby Receiver Unit. I can at the very least turn them on and off, and control volumes. Having to balance the TV volume with the VCR/DVD unit volume with the Dolby unit volume can be nerve wracking - at least now its all on one remote. Even though I still have to have the DVD/VCR remote handy for unloading DVD/VHS tapes, another for the Receiver - to switch between DVD/VCD/TV/CD/Cassette play, and another for the CD unit, which has no remote on/off capability. The Cassette player is not remote-enabled either, which is fine, as I rarely use it.