Charlie's question to Renatta?

That's a great question. And I'd love to know the answer.
When I was watching the movie, I was asking myself that same questions.
Initially I thought he was trying to figure out where she was going to run to with the money (so he could track her down if necessary).
But seeing as he was planning to shoot her and keep the money himself, I have no idea why he was asking her that!

1) He's tired, demoralized, kind of knows what he has to do (knowing how and where she will end, he wonders where did she begin?). Its also sort of a "who the heck are you really???" kind of question, in context.

2) It might be left over from the book. In the book, Charlie's interior monologue shows how curious he is about where she is from. The book makes it clearer that she's from somewhere in (probably) Eastern Europe. She reads novels in a language Charlie doesn't recognize, has a thicker accent than in the film, etc.

i actually know this, i think
i read the book and the book talks about renata and her origins more in depth so i think that line was trying to make a reference to the book; there's a lot of lines like that, where teh movie mentions something that is talked a lot in teh book

Why did Charles Foster Kane say "Rosebud" right before dying?

Who is John Galt?