Policy Based Routing and OSPF

I have 7 routers in an OSPF area all nicely sharing their routes (about 30) with one another.
For ONE router I want to specify a different default route for certain traffic based on source IP.
Policy Based Routing I hear you say.
However, if I create a policy based routing table for that traffic, do I have to include in it all my OSPF routes as static routes?
This is obviously not very maintainable.
It’s just the default route I want to change for these source IP, I want them to use the OSPF routes for all other traffic.