http://img109.imageshack.us/img109/2609/anqrimmen.jpg
Centred roughly on cell 15, -22.
You can see Bravil up north in the distance.
Its a very large, only slightly hilly area, just across the Elsweyr border, half way between Bravil and Leyawiin. You could connect the town to the main road, and have the canols empty into a channel flowing down to the Niben. A town wouldn't look out of place in that spot.
I think it also matches up with the official map.
@Lady Nerevar
It was surprising to see Rimmen appear in the novel. The last place I expected to see. It was cool to see a few slices of Elsweyr in it.