Thanks Henning,
Carrierroute rewrites the R-URI because you normally want to route your message according them. So this is hardcoded in the logic of the module. The from uri user (like you've tried above) can be only used as the user part for the R-URI. Mangling your from uri is normally not related to routing decisions. But you can use the uac module functions to change this, for example.
I understood that CR module is a scalable way to do LCR, I was just hoping that I could get From Uri mangling using the same prefix table provided by the CR module without rewriting a script logic to do a prefix lookup and then use the UAC module. Maybe in a next release :p
Thanks a lot for providing us this module.
regards, rod.