What version of GEOS is that? I seem to remember that GEOS 2.0 was being developed and was actually released a while ago. I may even have downloaded it. Unfortunately, I can't remember much about the C64 stuff I have archived.
If you go to file open it dosn't actually do anything
I think its designed for hd use, I think it would open a dir if it was set up on a hard drive/virtual hard drive.