you cannot export as csv, but thats not a big problem. The export is a mysql dump, within it is CSV data (sort of). Edit the dump file, and find the following lines which are the start, content and end of the usertable
LOCK TABLES userinfo WRITE;
INSERT INTO userinfo VALUES (1,1,'test123','','guest','d82002db1f2d1b79fd08426393b29fe1',0,0,0,'','',25306851,'','','admin','root',1,'','',25306851,'','','','','','','',0,'','',0,'','',0,'',0),(2,1,'test456','','guest','02f9239befa5452c662167e0f9a5a358',0,0,0,'','',25306852,'','','admin','root',1,'','',25306852,'','','','','','','',0,'','',0,'','',0,'',0);
UNLOCK TABLES;
now, save just these lines into a new file (or delete everything except these lines). The password is encrypted, not much way around that. You can then use a perl/python script to manipulate it and do what you want.
If you need the password and/or you're not so familar with scripting, then I would recommend you just do the following and save yourself some time:
a) ssh to controller
b) start session log on your ssh client
c) enter command "no paging"
d) enter command "encrypt disable" if you want to see passwords
e) enter command "show local-userdb"
f) stop ssh session log
g) now edit the session log file to just include the header and the output lines, get rid of the ----- and other junk
Name Password Role E-Mail Enabled Expiry Status Sponsor-Name Remote-IP Grantor-Name
test123 test123 guest Yes Active 0.0.0.0 admin
test456 test123 guest Yes Active 0.0.0.0 admin
h) save it and then import to excel as space delimited data
hth.