For example, I'm going to Paris next year. In Paris lives my acquaintance Helene. I say to her on the phone:
If we meet when I come to Paris next year, you can show me your city.
I know, on the basis of Google's search results, that "If we meet when I come to Paris" is wrong. Surely, I could say: I'm going to Paris next year. So if we meet, you can show me your city. But what should I say if I want to underline the "when I come to Paris next year" idea and at the same time cram all that into one sentence? That is, it comes out that one subordinate clause (If we meet) must have another one (when I come to Paris next year).
However, mostly, I'm interested in how a native English speaker would say all that idea.