How to add applications to LH end of panel (where Firefox is)?

[Chris G]

How can one add application launch icons to the LH end of the top
panel in xfce?  I.e. I want to add a launch icon for Evolution next to
the Firefox launcher.

If you just right click on the panel and use "Add Items to the Panel"
they get added at the right hand end in among all the applet icons.
I want to separate the launch icons from the applet icons.

-- 
Chris Green