SzFindSz returns a pointer to the first character of the first occurrence of the substring in the string. If the substring does not occur anywhere in the string, if lpszKey is larger than lpsz, or if either parameter is NULL, a value of NULL is returned.
The SzFindSz function searches for an exact match only; it is sensitive to case and diacritical differences. Searches in Unicode and DBCS formats are supported. The length limit on both parameters is in characters, not necessarily bytes.