Can I have a character say a Global Message rather than the "narrator" display it?
Otherwise I'll have to make a Message 0 in every room with the same message for the player to say when he talks to himself.
Or could I possibly handle it with dialog? Dialogs are also global, right? Or are they room-specific?
Choose "run script" as the action for talking, and use cSCRIPTNAME.Say("What to say");
"Oh, I see," says the blind man.
To clarify:
I'm assuming you're talking about the Player character's interactions (Look at = 'Game - Display message (999) (Damn, I'm looking good!). So, change the interaction to 'Run script' and make it:
cEgo.Say("Damn, I'm looking good!");
Or whatever script-o-name and message is appropriate for your character.