Sure. The standard and RTW calculators don't give any routes RIX-EBB, but the timetable lists an MS flight from Cairo on Tue and Sat, returning a Wed/Sun. So if I ask to book those on other days, they'd be OK with my going via JNB instead, and taking a stopover there?

I had a look further east too, but I was having difficulty finding two stopovers: most of the northerly places seem to go via CAI to get there, and then again on the way to RIX. MCT-RIX appears to have options (DXB/BAH/AUH), and DOH-RIX goes via RUH, but I haven't looked into which ones are actually plausible stopovers yet, or tried other routes (getting caught with the explosion of options!).

Any suggestions?

Thanks.