translating one objcaps language to another?

Does anyone know of a compiler that goes from one object capabilities  
language to another?  If you were working with such a tool, what you  
would want is to be able to reason in either the source language or  
the target language and not go wrong.  I would like to better  
understand what exactly this level-shifting means.

It looks tempting to say you want object graphs in the source  
language to map to object graphs in the target language.  If the  
source language has a reference from SA to SB, then you want the  
target language to have a reference from TA to TB where TA and TB are  
the objects corresponding to SA and SB.  Given this property, it  
would seem like you could shift your reasoning between the  
compilation levels pretty safely.

I am not sure, though.  What do you guys think?

-Lex