[CMake] custom cmake files

[Marie-Christine Vallet]

Hi,
I wanted to check for an non standard existing library (QGLViewer) and 
found a custom .cmake file  on Internet that will do that for me. The 
problem is that I am starting cmake, and do not know where to place that 
custom .cmake file
I found the custom .cmake file here: 
http://www-id.imag.fr/FLOWVR/manual/flowvr-suite-src/flowvr/cmake/FindQGLViewer.cmake
Could someone help me out on how to use this file, or point out a 
webpage that could help me out, I tried to find the information on the 
cmake web page, but did not find an obvious solution.
thanks,
Marie