How to insert a userfield at to cursorposition

[Egbert]

I am writing a extention that can pick up a field from a list, and insert that field in the current document.
I want to insert that field exactly at the cursorposition. But my application insert the field
at the beginning of the line where my cursor is.
Has someone an example (in java) how to insert a text or userfield at the cursor?

Thanks Egbert