[kh99]

It could be that you need to change the cookie path, in Settings > Options > Cookies and HTTP Header Options > Path to Save Cookies. If you have it set to something below where your custom page is, then the cookie that keeps you logged in will not be sent for your custom page.

Edit: Oh, I don't really understand the nodejs/port 3000 comment you added above. But you need the cookie to be sent or else you need the sessionhash value as a parameter (which is probably difficult to do unless users are getting to the custom page by clicking on a link in another vbulletin page).