Host_Header IRule for F5 LTM

Say I have the below vip setup in the LTM: VS: 10.186.41.15 for host www.test.com and is the only vip accessible to the user population. I then create another LTM VS vip: 10.186.41.16 for www.dummy.com, which is "not" accessible to the user population.

I setup my dns to have both websites, "www.test.com & www.dummy.com" to point to 10.186.41.15 for resolution.

I want to create an IRule and assign it to the vip 10.186.41.15, that says any incoming request which has "www.dummy.com" in the host_header, forward this request to the vip 10.186.41.16.