Did some searching but couldn't find anything on this. Does anyone have any experience with getting RTW tickets with different fare classes? Here's the story:

I have an employee based in HKG. She has to fly HKG-ORD (for a conference where everyone from our HKG office has to fly Y). From ORD, she and I will go to MUC and PVG (with her going back to HKG from PVG and me going on to MEX then ORD). We're allowed to travel in C (with the exception of the HKG-ORD section because of the directive), so it seems like the least expensive way is to book a RTW. Can I book her a ticket with the first segment in Y and the rest in C? Thanks.