You have an error in your code. On line 354, you have:
error = Excel_GetProperty (ExcelRangeHandle, NULL, Excel_AppSheets, CAVT_SHORT,&ExcelInteriorHandle);
You are trying to get the Excel_AppSheets property of the Range object. You should be getting the Interior property on the Range. That's why you are getting an error. If you correct that line to be:
error = Excel_GetProperty (ExcelRangeHandle, NULL, Excel_RangeInterior, CAVT_OBJHANDLE, &ExcelInteriorHandle);
You're program will work.
Best Regards,
Chris Matthews
National Instruments