You can do all of this from OSX
Verify that the mouse OS9 control panel is present in the Control Panels Folder.
If it's not there, look in the Control Panels (disabled) Folder.
A:If it's in there, move it into the Control Panels Folder and reboot. Should be problem solved.
B:If it was in the Control Panels Folder, go back to the ISO download, grab that panel again, swap it out and reboot.
(Just in case it got corrupted - not likely, but easy to try)
If that doesn't work, go to Macintosh Garden and download "USB Overdrive" (a universal USB mouse driver) and install it…
Oh wait…you can't because you don't have a working mouse… so
Go spend 10 bucks on ebay and buy a real Mac USB mouse. Should be problem solved.
If you must use a PC mouse, use the Mac mouse long enough to install "USB Overdrive"