In connection with my Computer Science Project work, I wrote a file splitter program. A simple C++ program. This is tuned to compile with my favourite g++ compiler. It may need some modifications to compile on some platforms.
You can download it here: filesplitter.cpp.zip
compile it as:
$ g++ -o splitter filesplitter.cpp
It is nice and handy tool to split files. Even it can work as a VCD cutter. It can split dat files :)