"Bake" values of multiple rotation controllers in list?

Say I have an object with several rotation controllers in a rotation list. I'm looking for a function that will take the resulting rotation of two or more of these controllers, and combine them into one (at the same time setting the values of the other controllers to zero). In other words, there would afterward be no difference in the actual rotation of the object, but the rotation values are now accessible in a single controller.

Other relevant factors:
1) The object is part of a chain, so parent object rotation may need to be taken into account.
2) The first controller in the list is an initial offset value, which should be left alone (in other words, simply taking the total resulting rotation of the object is not an option).
3) Some of the controllers being combined may have unequal weights, so their values would have to be combined accordingly.

I've tried this a number of different ways, but my background is in art and animation, not math. It's clear to me that I'm not going to find the correct solution for this on my own.