Another example of that sort could be: Were I to be given a class in which to teach whatever I wanted, I would choose to teach a language. OR Were I to pick a writer with whom to spend a day, I would pick Milan Kondra. OR Were I to be given an eraser by which to erase a part of world's history, I would erase the world wars. Explanation: The point is that whenever in a sentence we need to use one of the connectors like WHICH or WHOM, and a preposition like IN, AT, BY, FROM, ETC, the preposition goes before the connector. Another point which relates directly to your question is that sometimes after phases like IN WHICH, AT WHICH, FROM WHOM, ETC we immediately have a complete independent sentence and sometimes we have an dependent clause containing an infinitive (TO + VERB). your case is the latter. Check also these examples: She is the teacher from whom I learnt a lot. OR It is the neighborhood in which I spent most of my teenage years. Hope that was useful.