以下是一个示例，它使用VB.NET语言并使用参考角度将AutoCAD中的组进行旋转。

需要的命名空间：

Imports Autodesk.AutoCAD.ApplicationServices 
Imports Autodesk.AutoCAD.DatabaseServices 
Imports Autodesk.AutoCAD.Geometry 
Imports Autodesk.AutoCAD.Runtime

代码示例：

Public Sub RotateGroupUsingReferenceAngle()
    '获取当前文档和数据库
    Dim doc as Document = Application.DocumentManager.MdiActiveDocument
    Dim db as Database = doc.Database
    
    '用户选择要旋转的组合
    Dim peo as New PromptEntityOptions("请选择要旋转的组合:")
    peo.SetRejectMessage("请选择有效的组合:")
    peo.AddAllowedClass(GetType(Group), False)
    Dim per as PromptEntityResult = doc.Editor.GetEntity(peo)

    '提供给用户选择旋转的角度
    Dim pdr as New PromptDoubleResult
    pdr = doc.Editor.GetDouble("请输入旋转角度(以度为单位):")

    '打开事务和块表记录
    Using tr As Transaction = db.TransactionManager.StartTransaction()
        Dim bt as BlockTable = tr.GetObject(db.BlockTableId, OpenMode.ForRead, false) 
        Dim blkrec as BlockTableRecord = tr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite, False) 
        Dim gr as Group = tr.GetObject(per.ObjectId, OpenMode.ForWrite) 

        '获取组的几何中心点
        Dim geocen as Point3d = gr.GeometricCenter

        '将旋转角度转换为弧度值
        Dim rotang as Double = pdr.Value * (Math.PI / 180)

        '使用参考角度旋转组合
        gr.TransformBy(Matrix3d.Rotation(rotang, Vector3d.ZAxis, geocen))

        '提交更改并保存事务
        tr.Commit()
    End Using

End Sub