I'm not aware of a command (add-users, for example) that uses the R80 API for adding anything other than Administrators.
It is still possible to use dbedit on the management server to add these users from the CLI.
If you were to place your user ids in a single file, then you could script the addition of all x hundred users in one go. What I have below doesn't account for any comments, etc., but additional properties are available ("dbedit -local print users <username>") and can be used as needed.
# create a list of commands for dbedit to process
for i in `cat userlist`
do
echo "create user ${i}" >> newusers
echo "modify users ${i} auth_method SecurID" >> newusers
done
# This will have dbedit save the changes.
echo "update_all" >> newusers
# Use the newly created newusers file
dbedit -local -f newusers