Change order of markup for exposed views filter
You can create your own views-exposed-form.tpl.php file and move the submit button to the top, or add a class to it and use css to float left and right. This however would affect all exposed filter on your site.

If you want to alter the form you should use the function 

function MODULENAME_form_views_exposed_form_alter(&amp;$form, $form_state)


Your best option is however to try manipulating it with css.