In OutSystems, especially in Reactive 11, the support for manipulating Excel files is quite basic and doesn't include advanced features such as setting the sheet orientation from right to left. However, you can configure this orientation directly in Excel after generating the file.

If you need to do this programmatically, a common approach would be to use external libraries to manipulate Excel files. In a .NET context, for example, you could use the EPPlus or ClosedXML library. Below is an example of how this could be done using EPPlus in C#:

using OfficeOpenXml;

using System.IO;

// Ensure that the license context is set correctly for the library

ExcelPackage.LicenseContext = LicenseContext.NonCommercial;

public void CreateExcelWithRTL()

{

    var filePath = "Path/To/Your/File.xlsx";

    using (ExcelPackage package = new ExcelPackage())

    {

        // Add a new worksheet

        var worksheet = package.Workbook.Worksheets.Add("MySheet");

        // Set the sheet orientation from right to left

        worksheet.View.RightToLeft = true;

        // Save the file

        var file = new FileInfo(filePath);

        package.SaveAs(file);

    }

}

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To use this code, you would need to add the EPPlus library to your project. This can be done using the NuGet Package Manager in Visual Studio, for example.

Steps to use EPPlus in Visual Studio:

1. Open Visual Studio and your project.
2. Go to the "NuGet Package Manager" in the "Tools" menu.
3. Select "Manage NuGet Packages for Solution".
4. Search for EPPlus and install it.

After that, you can use the above code to create an Excel file with the sheet orientation set from right to left.

If you want to do this directly in OutSystems, you would need a custom extension that uses C# or another language compatible with the mentioned libraries to generate and configure the Excel file as desired.