How to leak aggregate/generated routes into another VRF

Hey all, Is there a method of leaking aggregate/generated routes to other VRFs so that the next-hop is modified to actually point to table where the agg/gen routes where created ? One way to do this, is to create a Null0 route and redistribute it into the BGP VRF process, but I would like to know if there is another way to do this ? Many thanks, Joe