But does your simulation work when you apply a logic high or low to the port pin, by means of, say a switch?

When you connected a voltmeter to the output of the LDR, what readings did you get when...

You don't need a ADC. Put the LDR in series with a resistor of about 10K and connect the output of the LDR to a port pin. When the Laser shines on the LDR, its resistance will be much lower than 10K...

You've explained what you need to do, but you haven't asked a question.
An LDR in a voltage divider would replace the switch, if your code works for a switch, it will work with a LDR. But it's not...

If P1.2 is set and you move P1.2 to C, then C is set.

MOV C, P1.2 simply moves the value on the port pin to the carry.

http://www.allaboutcircuits.com/vol_4/index.html
Chapters 7,8