rpc/rpc.h file not found on windows

I am working on sunrpc library developed by Sun Microsystems on windows.

I have downloaded GnuWin32 sunrpc4.0 on windows 10.

I am running rpcgen -a -C -Y "C:/MinGW/bin" add.x command and I am able to get .c , .h and Makefile files.

Now I am compiling using make -f Makefile. I am getting following error "fatal error: rpc/rpc.h: No such file or directory"

I have installed "rpcsvc-proto" package from cygwin tool. My rpc.h file location is C:/cygwin64/usr/include/rpc/rpc.h. I have included this path into environmental variables. Still I am getting this file not found error.

I have made following changes to my Makefile

CC = gccCFLAGS += -g -DRPC_SVC_FGLDLIBS += -lnsl RPCGENFLAGS =

Can somebody help me on this?

Thanks in advance.