Problem Solved
All,
It is fixed. As it turns out not only is the volume locked to the TV, the channel control is locked to the cable box.

I am reading though the channel control lock, which includes the numeric key pad, CH+, CH-, Enter, and Last. Now I am gazing, in my most loving fashion, at this new remote, and note that there is no "Enter" key. OMG, it hits me: the "Enter" key is actually there, but is operating undercover with the alias "OK/Select". Could it be? Could it be that the instructions for a piece of electronics were in error; that the instruction were not totally accurate!
I had do stop and rest. My heart was pounding, hands shaking, I was sweating, I dare not stand up on my weakened and shaking legs. I was able to gain my composure finally and with great trepidation pick up this new piece of electronics. I dried my other hand and methodically entered the sequence to unlock the channel control. The sequence completed, there was an eerie silence, an air of anticipation. Again I had to compose myself to try the now unlocked sequence.
I couldn't put it off any longer, I had to gut it through. I carefully aimed the remote at the TV and pressed "Power". It came on, (OK not a big deal, but I wasn't going backwards). I navigated to one of the TV setup menus and now I was ready for the moment of truth. I gripped the remote tightly, and using the first finger on my left hand, I pressed the "OK/Select" (nee Enter) key.
I fell back to couch, aghast: IT WORKED, the menu item was selected. Oh joy, Oh rapture!!!!! Quickly I moved to the old VDR, and yes, yes, yes, "OK/Select" (nee Enter) worked there too!!!!
I frozen in the moment. Could this have actually happened, was I dreaming? No it was reality, I was sure of it. I yelled at my wife to bring the camera and record this moment. She came running in thinking that there were deer in the backyard or pehaps one of the coyotes or wild turkeys. I told her of the great event. She muttered a four letter anglo-saxon euphemism, and some other phrases, which I dare not repeat, and ended with something that sounded like "Get a Life"! Little did she know I had life!!!! I had a Comcast Custom DVR 3 Device that worked! It doesn't get any better than this.
Now for a nice glass of vino in celebration. I am considering having a banner made to hang on the garage, but the wife is not so enthusiastic. She'll come around. For now, I am just going to enjoy a functioning "OK/Select" (nee Enter) key on my remote.
Doug: re Comcast support: OK I admit to weak moment.
Cheers,
Paul