Hi,
Sorry for the late reply, we were pretty busy in these days because of meetings and visit to the ISA show.
The closest thing you can do in RTD is Text Personalization, which allows to set variable fields. It had been introduced here:
http://support.realtimedesigner.com/forum/read.php?1,3528
What I am not understanding here though is if you're asking for ways for customer to upload such files, or for you (IE, meant to generate print files with the variations).
The answer is still no actually (that system is not based off of CSV files), but makes a difference in thinking at possible alternatives, such as API-based generation tools for variable data printing