Hello Ant,
It we take a 12Bit ADC (like the MCP3202) with a +5.00V reference, then 5V/4096 counts = 0.0012207V or 1.22mv per bit.

Instead of your example of 10.66V (you will have to scale this down to use it) , lets take an example of 2.33V:

2.33V/0.0012207V = 1908.74

that is: the ADC will output a count of 1908 counts if you feed it with a 2.33V.

I hope this has cleared up your queries, if not email.

Regards,
John.