In a tall glass, fill with ice 2/3 up. Add 1oz vodka and 1oz kaluha. Fill with cola 3/4 full. Top up with milk. Stir lightly. You can still curdle this drink if you over stir.
I have experimented, and you can trust my answer.
Step one - Make sure your glass can hold 9 oz. plus Ice.
Step two - Add 5 lrg. ice cubes to glass. Add 3 oz. Coke to glass filled with Ice first.
Step three - Use a tall shooter glass to combine Vodka, Kahlua, Milk. Both the Vodka and Kahlua and milk should be combined together separate from the coke (it's the coke that causes the curdling), not in the coke glass to prevent curdling!!! In your tall shooter glass combine 2 oz. Vodka and 1 oz. Kahlua and then 2 oz. of milk. Then pour it into the Coke and Ice. It works :)
OK you really have me scared now, so I'm not gonna ask what a paralyzer is. :D
I am guessing you have to heat it. Mix the milk with something else of significant quantity before heating. That might work.