I am having a lot of trouble hooking up my Comcast DVR to my Emerson (whack) DVD/VCR to my Sony TV. I want to be able to watch and record anything on my cable/dvr on the same channel as my vcr/dvd player. Any suggestions on what to use to hook it up?

You're question is very confusing, and I'm guessng the answer would confuse you (and probably myself!). Might be best to get one of the professional guys on this site to come out and have a look in person.
The call-out fee is generally very reasonable, and they will be able to inform you of any mistakes you may have made also. Worth it for the peace-of-mind.
Where are you located?

Actually the guy just installed it today. He installed the Comcast DVR and I tried to play my vcr/dvd recorder player and it did not play on the same channel as my cable. My cable was on video 4 and my dvd/vcr player was on channel 4. By the way these are the tv channels. I was wondering how to record/play my vcr/dvd recorder on the same channel. My fiance figured it out but it only works for the dvd side not the vcr side. The dvd/vcr recorder is a dual box. Now that he rewired some things he was able to play the dvd on the same channel that the cable comes on however I cannot view or record using the vcr side. It does seem confusing but I doubt comcast will tell me what someone else would. They would probably say it can't be done but I know it can. It would be pretty ridiculous if it wasn't possible to use all features (vcr/dvd recorder, dvr cable) on the same tv channel. I shouldn't have to change channels. When I press play on my vcr/dvd then whatever I am playing should pop up even if i was in the middle of watching regular cable tv. It should come back on when I press stop. It is as simple as that.

There are SO many ways to hook this up, it's silly. I would be happy to suggest the simplest way (for free). If you need something better, you would be best served hiring a professional to hook it up. Be prepared to spend a little money on cables...

So, here goes... (and sorry in advance if you already know some of the things I explain)

Cable (the kind with the screw-on connector) should come from the Wall to the Comcast DVR box "cable in" jack.

From there another cable (same kind) should come from the Comcast DVT box "cable out to TV" jack to the "Cable In" jack on your DVD/VCR.

From there, another cable (once again the same kind) should come from the "out to TV" jack of the DVD/VCR to the Antenna jack of your TV.

The ComCast box will be output on Channel 3, and you will have to set the output channel of your DVD/VCR from 4 to 3 by way of the little switch on the back marked "rf output channel" or some such.

By doing this, you will bypass any HD capability that you might have had (some info would have helped in this regard), and you will be getting the lowest picture quality possible, but you will get what you wanted - turn off the DVD or the VCR, and voila, you will have the cable box picture.