Same as the C preprocessor you can use the #include command to include other pre file
normally I prefer NAME.ORINGAL_FORMAT.p for main file NAME.ORINGAL_FORMAT.ph for include
file.
To use #define to define macros, just follows this format: #define [MACROS NAME] "[ITEMS]"
and to use macros just write the macros NAME.
To use comment, you can use #define COMMENT "Your Comment", just make sure you are not using COMMENT as your content