[Coco] Can I use a CoCo3 as a serial data sniffer/recorder?

[theother_bob]

I want to monitor a serial data line in my vehicle while a specific diagnostic operation is performed (programming the keyless remote.)

According to vehicle factory service manual the data could be 9600 or 38400 baud. 

What I want is basically a recording of the serial data during the entire process, which should take less than 2 minutes, and then I hope to be able to reproduce part of it at will (the last second or so).

Thanks for any guidance.

More detail on my problem, not CoCo related...
First of all, my car is a 95 model. I bought it used, didn't get the remote. Got one off ebay cheap. "FREE PROGRAMMING* (*most models... guess what!)  If it were 96-99 I could do this with a paper clip, but nooo...
I have to pay a GM dealer to hook up a Tech1 diagnostic tool, put the car in programming mode, press the remote buttons that the tool says to press, then (this is the kicker) press Yes on the scan tool to complete programming.

I can put the car into programming mode with a paper clip, but I have no scan tool to just say Yes. A GM dealer quoted me $80 just to do this. I told him he just priced himself out of a job. I can buy an aftermarket wireless remote kit for less than HALF that!! This kind of greed is why GM is dying a slow, steady death IMHO. They STILL don't get it, even today... sad.

So my goal is to find someone who will do it cheaper, but I also want to be able to bypass the dealer next time and maybe help others in the same boat. I hope to see what happens on the serial data line when Yes is pressed and replicate the behavior without the scan tool, thereby sticking it to "the man".