Have checked the diagram again, and you have correctly pointed out that the power for the fog lamp comes from the back of the 'DIP SWITCH' Which I guess is the switch on the left side of the wheel.
http://www.cobraclub.com/crcforum/user_files/1570.jpg
The numbered wires below are for (I Believe):
1) Live in from fuse box
2) Feed out when lights dipped
3) Feed out when lights on full beam
4) Feed out when switch gear pulled for full beam toggle
5) Power for above
Am I correct in these assumptions?
http://www.cobraclub.com/crcforum/user_files/1571.jpg
Dan ~
http://homepage.ntlworld.com/danny.mann/