Documentation

Configuration / SessionAuthenticator.config_prefix

This option enables override any config option from a session, the value of this option will be used as a prefix when it looks though the sessions for config options.

Please note that the prefix is REQUIRED and set to moxiemanager by default in the config file.

$moxieManagerConfig['SessionAuthenticator.config_prefix'] = "moxiemanager";
<add key="SessionAuthenticator.config_prefix" value="moxiemanager" />

So if you wish to overwrite the rootpath using sessions.

$_SESSION["moxiemanager.filesystem.rootpath"] = "/some/root";
Session["moxiemanager.filesystem.rootpath"] = "c:\some\site";