'新しいシートを挿入
Sub New_Sheet()
    Dim NewWorkSheet As Worksheet
    Dim Sheet_Name As String
    
    Sheet_Name = InputBox("シート名を入力")
    
    Set NewWorkSheet = Worksheets.Add()
    NewWorkSheet.Name = Sheet_Name
    
    Call InsertButtonOnSheet(NewWorkSheet)
    
End Sub

'ボタンを作る
Sub InsertButtonOnSheet(Insert_Sheet As Worksheet)
    Dim ws As Worksheet: Set ws = Insert_Sheet '作るシートを引数で受け取る
    Dim obj As Object
    
    'B2からC3の範囲でボタンを作成
    Set obj = ws.Buttons.Add(Range("B2").Left, _
                                 Range("B2").Top, _
                                 Range("B2:C3").Width, _
                                 Range("B2:C3").Height)
    With obj
        .Characters.Text = "Test Button"  'ボタン表示テキスト
        .OnAction = "Msg_Open"            '登録マクロ名
    End With
End Sub

'登録用サンプルマクロ
Sub Msg_Open()
    MsgBox ("こんにちは")
End Sub