Accessing, creating, deleting and modifying initialization files is both straightforward covered in the Consolidated WIL Help file. The functions include IniReadPvt, IniWritePvt, IniItemizePvt and IniDeletePvt. There is also a set of similar functions for legacy system initialization files that actually access the registry instead of a file in most cases. Those functions are maintained for backward compatibility, have the same names as the above except for the "Pvt" on the end of each name, and are seldom used on modern versions of Windows.
Unless you have a more specific question, you might wish to take a look at the functions' documentation in the help file.
