code: public function setSelectedCells($pCoordinate)
      {
          // Uppercase coordinate
          $pCoordinate = strtoupper($pCoordinate);
  
          // Convert 'A' to 'A:A'
          $pCoordinate = preg_replace('/^([A-Z]+)$/', '${1}:${1}', $pCoordinate);
  
          // Convert '1' to '1:1'
          $pCoordinate = preg_replace('/^(\d+)$/', '${1}:${1}', $pCoordinate);
  
          // Convert 'A:C' to 'A1:C1048576'
          $pCoordinate = preg_replace('/^([A-Z]+):([A-Z]+)$/', '${1}1:${2}1048576', $pCoordinate);
  
          // Convert '1:3' to 'A1:XFD3'
          $pCoordinate = preg_replace('/^(\d+):(\d+)$/', 'A${1}:XFD${2}', $pCoordinate);
  
          if (Coordinate::coordinateIsRange($pCoordinate)) {
              list($first) = Coordinate::splitRange($pCoordinate);
              $this->activeCell = $first[0];
          } else {
              $this->activeCell = $pCoordinate;
          }
          $this->selectedCells = $pCoordinate;
  
          return $this;
      }
docs: Select a range of cells.
  
  @param string $pCoordinate Cell range, examples: 'A1', 'B2:G5', 'A:C', '3:6'
  
  @return Worksheet