It looks like Ableton has a great deal of Rex files, or rex sounds because rex has already split them all. So it imports them very well.

ALC files contain a reference to the WAV or AIF file used for that clip. saving the set as self contained is probably the easiest way. Or— before you drag to browser and create the .ALC you can place the audio loop( wav or aif ) in an area of your Live Library that you know you have on both machines, the Waveform directory in your Library is good for this. So move the Wav or Aif file to the Waveform directory, make sure the clip still works in Live and that the clip is referencing the file in your waveform directory and not the older wav file - then drag to browser to make ALC. Then when you transfer to your powerbook, make sure to transfer the ALC file and all of the contents of your Waveforms directory to the same Waveform directory on your Powerbook. Also note you can do this from anywhere whithin your ableton Library folder as long as it is the same n both machines.