I'm assuming that you've already created the listview in the dialog's init event, so I'll go straight to adding the text.
You add the text the same as you would with any other dialog control, by using the /did -a command.
/did -a identify 3 %nickname $chr(9) $+ %network $chr(9) $+ %password
The $chr(9) (tab) seperates the text adding it to each column.
