All CabPack is is a relatively simple interface to
makecab.exe. If you want a command line CAB archiver, you could try Microsoft's own
cabarc.exe. I think it was included with the XP and 2003 Resource Kit Tools.
That said, PowerArchiver shouldn't have any problems adding folders to a CAB archive. Are you looking to have all the contents of the resulting CAB archive be inside a single subfolder?
However, CAB files are very sensitive to file order when it comes to compression level. If you can group files by type you can improve the compression by quite a bit in some cases. For that you'd need a tool to custom generate DDF files for you.
All this said: Why CAB? The only thing I can think of is that decompression is built into Windows XP and up, and the compression level can be significantly better than ZIP. However, 7-Zip can easily beat it on many filesets and the overhead of the SFX stub is minimal if you want to include it.