are you planning to add the 10oz vodka to the beer? want to see how much it changes the ABV? I just created a calculator for this ABV Adjustments on my beer calc tools page http://web.jomebrew.com/beercalc.htm
In the Spike section, say you have 5 gallons of beer at 6% ABV and are adding 10 oz of 40% Vodka. Just enter those in the calculator and you can see the affect on the ABV of the beer. Spoiler, .5% ABV.