How to use a core node inside of a custom node implementation

[cinhcet]

Have you tried this?

@cinhcet

you said you get this list from some server, right? I guess as a json file? Then find out how to use jquery to get a json file into the editor of your node, something like $.getJSON('http://YOURSERVER', function(data) { blablabla })

The link I posted should just tell you where you should put the $.getJSON, namely in the oneditprepare function.
Then you can have a dynamic list