Download
http://aminet.net/util/arc/lha.run copy it to ram: on your amiga and run it, its the latest command line version version of lha supplied in a self extracting lha archive.
If you then rename the correct version of lha for your cpu to lha (probably lha_68020) then copy it to c:
and use lha to extract the archive, before installing it.
Or just rename the file called "_" to " " after you extract the MUI archive with unarc from workbench before running the installer.
I have a subway USB card in my A1200 and it works very well after you install MUI.