Restrict access with mod_jk / ip address

I have configured Apache + mod_jk to redirect users pointing to /
dspace to be served from Jetty servlet container (Tomcat wont work in
this case). Now I need to restric the access to this service based on
IP's but I cant seem to make it happen. I think the restriction can
not be made from apache but has to be done via mod_jk (if possible) or
Jetty (dont know how!).

So Im wondering, could someone help me out here? How to restrict the
ip's redirected through mod_jk?

Thanks,
Mika