leo1434:
At the following site:
http://www.xprt.net/~s8/prog/orion2/lbx/
There is an explanation of the lbx file format, which includes a header that describes how many files are inside, as well as what their offsets are. You can then read the bytes and split them apart according to the header, but you won't necessarily know whether you have text data, graphic data or whatever.