Either that or the <IMAGE> tag wich allows you to configure icons seperatley.
One could also do this with the script file but seeing as you cant do this telling you that would only increase your conffusion.
try this..
var/faceBitmap=icon('face.dmi');//I dont recall wether the icon macro uses a file or icon_object to make the cion appear but just to be safe Ill create an object.
client/verb/Say(t as text) { world<<"-\[\icon[faceBitmap]]-[src]:[t]"; }; //also I wouldn't use this function as is if I were you.The faceBitmap is a pointer to icon() wich creates a new icon(as is its defininition) so for the sake of effieciency dont use it as supplied (unless you dont care it all comes down to your final word)