gnu make – Using Gnu autotools library in CMake project

I want to ask you a little question. In a project based on gnu-autotools I can use use my library(libtest based on gnu autotools) with a construction "pkg-config --cflags libtest" for include directory.

But the project based on Cmake I must use *.cmake config files (Or construction include_directories ("/usr/local/include/libtest") but this is ugly in my opinion).

How can I write and add this *.cmake files in my library? Do you know any library where I can see example? Or where I can read about this?

Regards, max