Transform a string to a serial date
static long StringToLSerial( const TCHAR* str );
A string containing a date. Excel will use the date formatting rules currently in force to read the string.
An Excel integer serial date value.
This function calls Excel's DATEVALUE() function to transform a string date into its components.
Because it uses Excel for the transformation, it handles variations in the Excel base date transparently.
If a call to the Excel API fails, then an exception of type CXlApiException will be thrown. Since this exception is derived from CXlRuntimeException, it will be caught by the add-in wrapper function when this method is called from within an add-in function.