Can anyone tell how to record the dvr recordings from the cable box to a CD disc?
I assume you mean DVD, and not CD. If you have a standard DVR, you'll have to transfer the recordings the old fashion way: using analog and in real time. In other words, the copy will be somewhat degraded and a one hour movie will take you an hour to copy. You simply hook up your DVR like oldtimers did with VCRs. A/V output from your DVR to A/V input on your recording device. You will most likely be using RCA composite jacks (the yellow, red, white ones) or if you're lucky, a SVideo jack for video.
Your recoding device will be either a DVD recorder (which you can find for less than $100) or your computer. If you use a DVD recorder, see if you can find one with a hard drive (VERY rare in the US. Pioneer stopped selling them in the US many years ago) and high speed transfer. The hard drive allows you to do some editing before finalizing everything on DVD. You can do even more sophisticated editing on your computer but it's more complex and time consuming.
If you really did mean CD and not DVD, you'll definitely need a computer since standalone VideoCD (VCD) recorders don't exist anymore. LiteOn made one about 8 years ago that recored VCDs as well as DVDs. The computer is needed to compress your video to fit the CD/VCD, which holds much less data. There are very few reasons to make VCDs, however, since most US DVD and BluRay players won't play them. And the quality is MUCH worse. Furthermore, blank DVDs are often cheaper than blank CDs (I bought 100 blank Memorex DVDs for $6.99 at Staples). VCDs and SVCDs are only used in Asia these days.
Another choice is to convert the videos into a file, i.e. AVI or MP4. Depending on your bitrate and what compression scheme you use, i.e. XVID or H.264, you can often fit many hours of videos onto a single DVD -- often at a higher resolution than a standard DVD (720x480). In fact, that is the only way to save HD videos without using BluRays.
Please note that any HD programming on your DVR will transfer in standard resolution since you can't transfer HD data through composite A/V or SVideo. The only way to currently transfer HD data to your computer is through your network and most DVRs don't have this capability. Tivo does, but you stated that your DVR is not a Tivo.