Dialout with failover destination

I am trying to figure out how to use the dial command which will failover to a secondary destination if the first one fails or times out.

some thing like dial(SIP/100@1.1.1.1&SIP/100@2.2.2.2) will dial both servers and whoever answers wins. What I need is to dial the first SIP destination, it that fails or times out, then to dial the second SIP destination.

Thanks

Two consecutive Dial application calls, one for each route.