source routing is done exclusively with the acl option 'prefer'.
So, you will need to catch your traffic with the correct acl source/destination info and then use the 'prefer' option to determin where to forward the traffic.
ie:
acl 1
clause 10 permit ip 10.10.10.0/24 destination 10.10.20.0/24 prefer serviceA
clause 99 permit any any destination any
apply ...
Gilles.
