One of the possible ways is to create a SQL-based table and a table view
based on that table. Then, create C1DataSetLogic objects (from the context
menu of C1SchemaDef) and wire to the BeforeGenerateSql event.

private void dataset_DataSet1_BeforeGenerateSql(object sender, C1.Data.GenerateSqlEventArgs e)
{
    if (e.TableView.Name == "MyTableView")
    {
        e.Command = new OleDbCommand(
            "SELECT TOP 5 Field1, Field2, Field3 FROM SomeTable",
            (OleDbConnection)e.TableView.Diagram.Schema.Connections["Connection"].DbConnection);
        e.Status = DataSetEventStatusEnum.Skip;
    }
}

However, it may be more easier to use standard OleDbDataAdapter with custom SQL
statement for this purpose.

Regards,

Well, would it be possible to give 2/3 code snippets where you are using
> the new clone function to copy sheets from one book to another?

Sure, I hope this is enough:


    c1XLBook1.Load(dlg.FileName);
    C1XLBook cloneBook = CloneBook(this.c1XLBook1);
    cloneBook.Save(dlg.FileName + "clone.xls");

    private C1XLBook CloneBook(C1.C1Excel.C1XLBook book)
    {
        C1XLBook clone = new C1XLBook();
        clone.Sheets.Clear();
        foreach (XLSheet sheet in book.Sheets)
        {
            clone.Sheets.Add(sheet.Clone());
        }
        return clone;
    }