Retrieves an object from the rules collection.
HRESULT item( long index, IHTMLStyleSheetRule **ppHTMLStyleSheetRule );
Returns S_OK if successful, or an error value otherwise.
This function returns an S_OK even if the element is not found. The programmer should check the value of the ppHTMLStyleSheetRule pointer returned by this call. If the value of the pointer is NULL, the element was not found and the call was not successful.