Smoking Ribs in Char Griller Side Grill ONLY

By the "side grill" i assume you mean the semi portable one that is comparable to the side fire box on the larger one.  Best i could think of would be to build a small fire in the corner and monitor the temperature.  The problems you are going to run into are that the area is so small that the temps you are going to get are going to be hotter than you want for smoking.  There is not much room to work around in the side grill which is going to be the biggest issue but you never know what will work until you try it.  Personally i think it wouldn't work as a smoker and would only be really good for grilling, you will experience much better results going with the larger one which i have had for a couple of years now.  There are also other kinds of smokers out there like the electric ones (personally i don't like them) that can be smaller and may suit your needs better.

Maybe you could start them in the oven and finish them on a low fire with sauce on the grill

I have that exact grill.
It's extremely difficult to maintain a constant low temperature in it for an extended period of time without a lot of fuss.
I put charcoal in a tin can with holes in it, adding more charcoal as needed, but it's a pain in the butt!!

You may have to cut the racks in 4 bone pieces and put them as far away from the fire as possible. I think that an 18" Uniflame charcoal grill might better suit you if you want ribs, I've cooked them on one before with good results. They're on closeout at my local WalMart for $10 right now, maybe you can get a deal in your area, too.