function adjustStartPoint(rowIndex, cellIndex, cell, isSelectedCell) {
    if (rowIndex === _startPoint.rowPos && _startPoint.colPos >= cell.cellIndex && cell.cellIndex <= cellIndex && !isSelectedCell) {
      _startPoint.colPos++;
    }
  }
Process validation and adjust of start point if needed

@param {int} rowIndex
@param {int} cellIndex
@param {object} cell
@param {bool} isSelectedCell