FRENAME
NM and CM callable.
Renames an open disk file (and its lockword, if applicable). The file
being renamed must be either:
* A new file.
* An old file (permanent or temporary), opened for exclusive access
with the exclusive option of the HPFOPEN/FOPEN intrinsics, and
with security provisions allowing write access.
I16V CA
FRENAME(filenum,formaldesig);