Something that's important to remember right from the start, is that the following "calories per gram" that you see plastered everywhere are only approximations: fat = 9, alcohol = 7, carbohydrates = 4, protein = 4. For instance, oleic acid, a very common fatty acid in olive oil, actually contains 9.41528 calories per gram. When people start counting calories like they count grams of flour in their dough, this has to be taken into consideration. Knowing this, you can see why there isn't an exact answer to your question. Foregoing exactness for the moment, in general, the impact to calorie content as a result of cooking is negligible, far more negligible than the difference between 9 and 9.41528.
You have to think of calories (kilocalories in the world of Chemistry) as what they really are: units of energy, and how the human body extracts energy from molecular bonds. Essentially, if the gastric acid is strong enough or an enzyme is produced in the body that can catalyze the reaction of the molecule, any molecule, so that the remaining molecule(s) are of a reduced carbon or hydrogen bonded structure type, then the body can usually use it as fuel by oxidizing it. That's why humans can metabolize alcohol. The body produces two enzymes called alcohol dehydrogenase and aldehyde dehydrogenase which break down and oxidize alcohol into acetic acid. The energy is extracted from the molecular bonds being broken and reformed into even simpler molecules.