Hm...just a theory here, and I don't know how possible it is, but...
What if you added grid notation to the map window (like on a paper map where letters run across one axis and numbers another and you can referenc general areas by a letter/number location.) Once you had this ability to reference areas on the map easily you could mod the Inventory.HTML window to do a simple HTML/JavaScript search for the quest/npc/mob/whatever and return the map name and grid reference. Not exactly what Killarny was asking for, but it's the only way I can think of to even come close to it.
Edit: the down-side being, other than an added graphical mod to the map frame, that you'd have to maintain two PoI lists, which would seriously complicate things and increase the risk of one or the other being out of sync.
Edit2: Editted for clarity...I hope.
Really bad ASCII art example:
Code:
A B C D E F G H
1
2
3 ^
4 x
5
6
7
8
Say I search for the 'x', the Inventory.HTML window would return Commonlands (East) D4, while the '^' would return Commonlands (East) G3 and so on.