wxWidgets toolbar text alignment

I am trying to add static text to my wxWidgets toolbar, but I can't figure out how to horizontally align it.

The code I am using is:

wxToolBar *m_toolbar;
wxStaticText *txt;

m_toolbar = CreateToolBar();
m_toolbar->SetToolBitmapSize( wxSize( 24, 24 ) );

txt = new wxStaticText( m_toolbar
                      , wxID_ANY
                      , "Sample Text"
                      , wxDefaultPosition
                      , wxDefaultSize
                      , wxALIGN_CENTRE );


m_toolbar->AddControl(txt);

I have seen a few posts about creating a custom version of wxStaticText::DoGetBestSize() but that hasn't helped either.