// CheckBoxCellTypeを設定します。
CheckBoxCellType cb = new CheckBoxCellType();
cb.IsThreeState = True;
cb.IndeterminateContent = "保留";
cb.FalseContent = "却下";
cb.TrueContent = "承認";
GcSpreadSheet.Workbook.ActiveSheet.Columns[2].CellType = cb;

' CheckBoxCellTypeを設定します。
Dim cb As CheckBoxCellType = New CheckBoxCellType()
cb.IsThreeState = [True]
cb.IndeterminateContent = "保留"
cb.FalseContent = "却下"
cb.TrueContent = "承認"
GcSpreadSheet.Workbook.ActiveSheet.Columns(2).CellType = cb

CheckBoxCellType chk = new CheckBoxCellType();
chk.Content = "承認";
chk.Command = new MyCheckCommand(GcSpreadSheet);
GcSpreadSheet.Workbook.ActiveSheet.Columns[0].CellType = chk;

Dim chk As CheckBoxCellType = New CheckBoxCellType()
chk.Content = "承認"
chk.Command = New MyCheckCommand(GcSpreadSheet)
GcSpreadSheet.Workbook.ActiveSheet.Columns(0).CellType = chk

public class MyCheckCommand : System.Windows.Input.ICommand
{
    private GrapeCity.Wpf.SpreadSheet.GcSpreadSheet _gcSpreadSheet;
    public MyCheckCommand(GrapeCity.Wpf.SpreadSheet.GcSpreadSheet gcSpreadSheet)
    {
        this._gcSpreadSheet = gcSpreadSheet;
    }
    public bool CanExecute(object parameter)
    {
        return true;
    }
    public event EventHandler CanExecuteChanged;
    public void OnCanExecuteChanged()
    {
        if (CanExecuteChanged != null)
            CanExecuteChanged(this, EventArgs.Empty);
    }
    public void Execute(object parameter)
    {
        if (parameter is CellCommandParameter cellCmdParam)
        {
            MessageBox.Show(string.Format("[{0}, {1}]セルです。", cellCmdParam.Row, cellCmdParam.Column));
        }
    }
}

Public Class MyCheckCommand
    Implements System.Windows.Input.ICommand

    Private _gcSpreadSheet As GrapeCity.Wpf.SpreadSheet.GcSpreadSheet

    Public Sub New(ByVal gcSpreadSheet As GrapeCity.Wpf.SpreadSheet.GcSpreadSheet)
        Me._gcSpreadSheet = gcSpreadSheet
    End Sub

    Public Function CanExecute(ByVal parameter As Object) As Boolean
        Return True
    End Function

    Public Event CanExecuteChanged As EventHandler

    Public Sub OnCanExecuteChanged()
        RaiseEvent CanExecuteChanged(Me, EventArgs.Empty)
    End Sub

    Public Sub Execute(ByVal parameter As Object)
        Dim cellCmdParam As CellCommandParameter = Nothing

        If CSharpImpl.__Assign(cellCmdParam, TryCast(parameter, CellCommandParameter)) IsNot Nothing Then
            MessageBox.Show(String.Format("[{0}, {1}]セルです。", cellCmdParam.Row, cellCmdParam.Column))
        End If
    End Sub
End Class