From the documentation I can see that one can add an NCommand, NComboBoxCommand, or NListBoxCommand to a command bar.  I'm interested in having an NTextBox on my command bar.  Is that possible?  I was looking for a tutorial or some help on creating my own command type and the documentation indicates there is much flexibility but I can't tell if it supports this.  If this is possible can you provide some help getting started doing this?