Returns the COM interface name of a refguid if known.
Returns a symbol naming the COM interface of refguid, which must be a refguid object known to Lisp.
(refguid-interface-name
(make-guid-from-string
"00000000-0000-0000-C000-000000000046"))
=> i-unknown
LispWorks COM/Automation User Guide and Reference Manual - 23 Mar 2017