I found this on another forum in an old post- but i am not sure exactly what to do
LHA files are archive files just like Zip, RAR, Tar, etc. You need a program to unarchive them.
1) Download and copy this to your Amiga:
http://aminet.net/util/arc/lha.run (it's a self-extracting LHA archive, which contains the actual LHA programs for differecnt CPUs)
2) Open the shell and cd into the dir you have the "lha.run" file. Run the file by typing: lha.run
3) As you have A1200, a safe bet is to install 020 version to your system. Type in the shell: Copy lha_68020 C:lha
4) Now you can unarchive any LHA archive by typing: lha x archive.lha destinationdir (for example: lha x term.lha ram: )
I will look for the shell as it seemed to disappear somehow- maybe hidden in a window dunno.