source files: xfil.[ch]
DO NOT USE THIS FUNCTION.
It is used internally by XFIL-LOAD-GRAPHICS-FILE, and has the effect of replacing (sub)expressions such as (XFIL-REF "myfile.lsp/12") with a reference to the named object.
However, IT WILL ONLY WORK CORRECTLY DURING A CALL TO XFIL-LOAD-GRAPHICS-FILE, since the datastructures used by this call do not exist at other times.