We are in Australia and the Jeppesen database costs your first born here.
I have loaded all the Ausie airports as user waypoints, which are very kindly made available on this very forum
All the ID's are in the form Yxxx, (eg YABA for Albany). I believe these are unique worldwide.
The problem I have, is that the tab "USR" does not show when DirectTo is pushed, so I have no way of picking a user waypoint using the DirectTo button.
USR does show when Nearest is used or when entering a flight plan.
This is quite vexing and is very easily accomplished on any other system I have used.