Most people would probably not need a guide for this but better safe than sorry.
BeSliced is a front-end for BeSplit that allows you to create dummy files. It supports AAC, AC3, WAV and MPx input. It will put the first frame of the output format (32ms for AC3, which is the format we're most interested in) to a separate file.
Once you start up BeSliced you'll see the following window.
Drag and drop your file to be split from explorer into this window. BeSliced will then automatically split it and close. The output file will be written to the same directory as the input file and will have a _Sliced01 in its name.
For instance: The input file is test AC3 T02 2_0ch 224Kbps DELAY -80ms.ac3 and the output would be test AC3 T02 2_0ch 224Kbps DELAY -80ms_Sliced01.ac3.