var instance = new GcSpread.Sheets.Calc.Expressions.SheetRangeExpression(startSource,
                                                                        endSource,
                                                                        startRow,
                                                                        startColumn,
                                                                        endRow,
                                                                        endColumn,
                                                                        startRowRelative,
                                                                        startColumnRelative,
                                                                        endRowRelative,
                                                                        endColumnRelative);
var value; // Type: Object
value = instance.getRange(baseRow, baseColumn);