I don't know of a single config example, but this link with regards to DMVPN may give you some insight.
http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a008014bcd7.shtml
Basically, if you are running routing protocols over the WAN, say OSPF, and you want the site-to-site VPN to be used as a backup, then you would run another instance of OSPF, or a different routing protocol (say rip v2 or eigrp) over DMVPN using GRE and IPSec. Then at the receiving routers, you redisribute the DMVPN received routes into the Frame-Relay (FR) protocol with a higher metric that what is advertised by FR, otherwise you would prefer the IPSec/DMVPN routes instead of the FR routes.
Let me know if you need more help.
