[j-nsp] redistributing label between rsvp and ldp

[Uzi Be]

hi,
I was just testing out to swap labels between two different signaling protocols (ldp and rsvp). lets say we have two different network, one is running ldp and the other one is running rsvp (same AS, so no inter-as options). 
ce - pe1 - p1 - p2 - p3 -p4 -pe2 - ce
so pe1 - p1 - p2 -p3 are running rsvp and p4-pe2 are running ldp, and edge ce's are using l3vpn. what are the options to have a labeled path from pe2 to pe1 (considering that pe1 is not going to run ldp protocol, and pe2 can't use rsvp so ldp tunneling is not an option here).
thanks in advance for your comments.
Andrew