midl /h filename
midl /h tlibhead.h filename.idl
midl /h "midl.h" filename.idl
The /h option is functionally equivalent to the /header option. The /h switch specifies filename as the name for a header file that contains all the definitions contained in the IDL file, without the IDL syntax. This file can be used as a C or C++ header file.
General MIDL Command-line Syntax, /header