The reason for saturating the oil/butter with THC is because it will get into your system better this way (I don't know why, it just does).
Here's what I would do. Find out how much oil is needed for the recipe. Use butter instead. Melt your butter. Ground your pot. Mix the two. (If there is not enough liquid, you can add water, but then you will have to refrigerate after straining so you can seperate the water from butter and pour the water off). Heat with a very low heat for about an hour. Strain your pot out of the butter using a coffee filter, squeezing as much liquid out as possible. Remeasure your butter and add more (oil or butter) if it's needed for the recipe.
24 cupcakes? I would use 1/4 gram per cupcake.