Set focus back to the application window after showing userform

When showing a userform (running its `Show` method) it not only shows up on the screen but also takes the focus (the destination of e.g. keystrokes). Say, the userform is a custom made toolbar. Its `Show` fires in `Workbook_Open()` but the form itself is used relatively rarely so we want the focus to go back to the main application window right after its appearance. Unfortunately, it seems `SetFocus` method is not valid for application objects. So how is this done? I suppose the solution for my example comes after ``` Private Sub Workbook_Open() [...] UserForm1.Show ```