Custom Drupal view filter
It depends what kind of content the view is displaying, but in general

Set the view path to be user/%/cj
Add a new argument (or contextual filter D7) > User Uid
This will work for any user id you insert, eg user/1/cj, user/20/cj, etc...

You can also set the filter to filter on user > Current user, but that would make the path user/1/cj ambigious.