send syslog to another virtual-router

Hi,

I send logs to an external syslog server:

system { syslog { host 10.16.0.22 { any any; } }

My SRX can route to this external server only through fe-0/0/1.0:

interfaces fe-0/0/1 { unit 0 { family inet { address 10.16.2.2/30 } } }

The inerface is on a virtual router:

routing-instances {
vr1 {
 instance-type virtual-router;
 interface fe-0/0/1.0;
 routing-options {
  static {
   route 10.10.0.0/16 next-hop 10.16.2.1
   }
  }
 }
}

Question: how do I get the log messages destined for 10.16.0.22 to go out via routing-instance vr1?

Setting a 'source address' did not work:

system { syslog { host 10.16.0.22 { any any; source-address 10.16.2.2;} }

Thank you,

Chris