Side quests

[macial]

How can I have NPCs give the player side quests the same way the campaign does it, i.e. they display a yellow exclamation point, then when the hero is close to him and right clicks they get the quest and the exclamation point disappears?

 

[Drakethos]

event- player selects (cant do right click) Unit
action- Create Special effect on unit using talk to me attached to overhead