if you have wb 2, you should have crossdos. check storage/dosdrivers. if there's a pc0 you're in luck. double click on it and now you can use 720k dos formatted floppy disks.
if you have a spare dd disk, format it 720k on your windows (there's a command to do it for windows xp, but it excapes me at the moment) put lha and lha'ed sysinfo in this disk. and expand sysinfo at amiga side. you also unzip sysinfo and copy it directly to disk, but dos filename restrictions will mess amiga filenames.
if you don't have a dd disk, you can use a hd covering the extra hole with a duct tape.