I don't think that is easly done with CAN communication. You have a clock line and a data line. You don't have to drive the data line if you want to talk on it, you only have to pull down. So you can't simply not connect a wire (as in a Rx/Tx configuration) but you have to make the sillicon chip unable to Tx. This requires new sillicon chips, and even then I don't know how well they can pull it off. So this solution is far from trivial.