Much appreciated emufan
...strange that this doesn't seem to work in the later version 1.21 though.
Anyway, managed to compile LHA 1.50 that you linked to and then used the 1st syntax that you provided. I now have 3 files:
a) <filename>.lha
b) <filename>.l01
b) <filename>.l02
Now for the next problem; how do I extract them? Note that each file will be on a separate disk so I guess I need to call each one in turn somehow?