[Zope] changing http port with -w

Hi everybody, im new to zope. Ive got this small issue to solve. I need to run the http of zope on port 40000 (because the admin lost the password to the router here and that happens to be one of the open ports here). I am running zope as a service on a win2k box. (latest stable version). Ive tried the -w flag in the runzope.bat in the bin dir. And ive also added the flag as a parameter to the windows service. Unfortunatly, neither work. Can anybody suggest a solution to this problem? Thank you Anton