How to convert only particular row and column as dataset?

i have  one excel document and Multiple sheets i ahve upload and convert to data table using below code
FileStream stream = File.Open(SourceUpload.Fullpath, FileMode.Open, FileAccess.Read);
IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);//xlsx file format
ds = excelReader.AsDataSet();
this code convert whole excel if 100000 rows is available.i want only 1000 rows and 1000 columns only how to get this one i will refer many codes i dont get any solution.is this possible how to do it.