Synchronous Calls in a routing rule

Hi,

I need to route a message synchronously to multiple targets using a routing rule.

In IRIS I built a general routing rule set, made up of a couple of rules. For one Rule in particular, and based on a common condition, I want to send the incoming message to 2 different targets. (no transformation is used)

I can select, in the single SEND action, multiple target names, or, I can create consecutive SEND actions, one after the other, each sending to their specific target.

The issue I have is that I want to do this routing synchronously, and only send the document to the second target, after the first target has finished processing (returns some response).

I know that - rather than using a routing rule, I can use a Business Process, however, I was hoping to avoid that if I can.

Any ideas how to send synchronously from a generic routing rule ?

Thanks - 

Steve