Private Sub CommandButton1_Click()
With ThisWorkbook
    .VBProject.VBComponents.Import Filename:= _
        .Path & Application.PathSeparator & "UserForm1.frm"
End With
End Sub

Private Sub CommandButton2_Click()
    UserForm1.Show
End Sub

Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer)
    Set iVBComponents = ThisWorkbook.VBProject.VBComponents
    For Each iVBComponent In iVBComponents
        If iVBComponent.Type = 3 And iVBComponent.Name = "UserForm1" Then
            iVBComponents.Remove iVBComponent
            Exit Sub
        End If
    Next
End Sub