Hi Trailrr,
first of all, you are not using the latest Beestack codebase. the latest version is 1.0.3.
To answer your question. there is not a single buffer that "just" contains the data that is received by the ZED.
The data recieved in an ZigBee is recieved in function called BeeAppDataIndication() in Beeapp.c as a pointer to a message.
I would recommend that you read the ZigBee application user's guide in order to learn how to use the demo application that comes with Beestack, and read and follow the instructions in The Beestack Application Developer's users guide in order to learn how to develop a ZigBee application.
BR,
Mads