Well, since no one has replied yet, I thought I would let anyone who has this problem know what I will be doing as a possible temporary work around.
I will cut the wire that runs from the BC to the drivers side brake light. I will then piggy back the left (working) brake light to the right brake light. This will obviously throw up an error message on the dash at startup.
To bypass this I will fit a resistor to the wire running from the BC to mimic the bulb. This will make sure no error message pops up and the computer will see it as a bulb. The problem with this is, overnight the battery will drain!
To avoid this, just before the resistor on the wire from the BC, I will fit a 12v relay. To this relay I will also have a wire from a remote off wire (such as the cigarette lighter) which drops to 0v when the ignition is switched off.
What this will all mean is, when I switch the car on the relay will close the circuit (because power will come from the cigarette lighter wire) and will mean that the resistor mimicking the bulb will prevent the error message on the dash. When I switch the car off, power is lost to the relay and it will hence open up the circuit - making sure that the battery does not drain over night.
There is one last issue I am predicting depending on how the computer checks for resistance. It may see the piggy back as having too much resistance (as opposed to too little) and throw up an error. Hopefully this doesn't happen, however if it does, I could use LED replacement bulbs and a single resistor tricking the computer into thinking there is only one bulb (LED bulbs use virtually no power and have next to no resistance).
I welcome anyones thoughts, especially if I am talking a load of cr*p!!!
I know this is a lot of work and admin, however for someone who cant afford to replace the expensive computer for a while, its only going to cost a couple pounds to do so may help someone in this situation.