i wonder if anyone has an issue like this?

we and an edu with ~400 staff and ~5000 students (including alumni).
Our GAL is external openldap with a sturucture like:

Code:
OurEDU --                 
                  |
                  -- People -- Staff
                                |
                                -- Students
when I do a GAL search i need to start the search a OurEDU.People to include both staff/students.

Some (Non-Academic) staff just want to search for other staff members and not students
(because the list is so long). As a work around i ask them to search for:
lastname@staff -> to return all staff with the lastname e.g. bloggs (bloggs@staff)
lastname@students -> to return all students with the lastname e.g. bloggs (bloggs@students)

Is there any other way around this i.m kinda stuck because the GAL search is global to a DOMAIN

GAL search is:
Code:
GAL mode: 	
External
Most results returned by GAL search: 	
100
Server type: 	
LDAP
LDAP filter:* 	
(&(|(mail=*%s*)(gecos=*%s*)(uid=*%s*)(cn=*%s)(sn=*%s*)))
Autocomplete filter: 	
externalLdapAutoComplete
LDAP search base: 	
dc=people,dc=ouredu
LDAP URL: 	
ldap://ourldap:389
Any feedback appreciated