The IResponse::AppendToLog method adds a string to the end of the Web server log entry for the current request. The log entry can contain a maximum of 80 bytes. For more information, see the AppendToLog method of the Response object.
HRESULT AppendToLog(
BSTR bstrLogEntry //binary string to append to the log entry
);
This method adds a string to the end of the Web server log entry for this request. You can call it multiple times in one section of script. Each time the method is called it appends the specified string to the existing entry.