var range = worksheet.Range["A5:B7"];

//Set value for cell A7.
range.Cells[4].Value = "A7";

//Cell is B6
range.Cells[1, 1].Value = "B6";

//Row count is 3 and range is A6:B6.
var rowCount = range.Rows.Count;
var row = range.Rows[1].ToString();

//Set interior color for row range A6:B6.
range.Rows[1].Interior.Color = Color.LightBlue;

//Column count is 2 and range is B5:B7.
var columnCount = range.Columns.Count;
var column = range.Columns[1].ToString();

//Set values for column range B5:B7.
range.Columns[1].Interior.Color = Color.LightSkyBlue;

//Entire rows are from row 5 to row 7
var entirerow = range.EntireRow.ToString();

//Entire columns are from column A to column B
var entireColumn = range.EntireColumn.ToString();