There is no miracle solution.
You have to check the hosting server document root directory.
See if it correspond to you JMS slave site deploy directory.
Review the tutorial video 0
www.jms2win.com/tutorial#jms12x-0
that present the concept relative to the adminstration of a server and also the CP-04
www.jms2win.com/tutorial#jms12x-CP-04
that show how to configure a slave site with a deploy directory and the expected results in terms of symbolic links.
Configure a hosting server to redirect an URL to another one will not work because this modify the URL and therefore the URL is not correct.
You can NEVER use a hosting server redirection.