Need to build custom menu item incorporating username

Hi

I thought It was going to be easy but maybe I'm missing something..
my site is http://geosz.com/mystories
It allows a user to see what services Im offering and then a plugin allows them to Register and Login.
The theme is a rockettheme one using Gantry framework...
The Login plugin will redirect the user to a different menu menu items are upload, order,view your stories (videos) and logout.
Upload is using another plugin which allows the logged in user to upload photos to their own directory ... it has as a parameter %username% to determine if it needs to create the directory or if it exists to upload photos there.
All these are ok and work for all users with the exception of view your stories...
Here I needed a menu item which went to the logged in user video page...
So I created a page called mystorieskempinski, then for this second menu I created a custom menu item called http://geosz.com/mystories/mystories%username%
So when I login as kempinski (this is a test account - the password is aaaaaaaa) I expect to click on that menuitem and display the page http://geosz.com/mystories/mystorieskempinski/ ... but nothing happens when I click the menu item

Anyone help me please
??

thanks

george