C:SIERRAArcanumdataportrait you need to create the portrait folder and also add the file userport.mes file in the same folder. Details on the userport.mes file can be found here C:SIERRAArcanumDocumentsportrait.txt it is fairly strait forward from here.
He'll never find this jinxed. It's really not a mod question. It's a question on how to import your own pictures, which you can do and use them in the real game, thus it belongs in the general discussion forum. In fact I used my avatar from TD to create a half-elf female character and played though the normal game with her. This is just my opinion but I doubt he will respond to it here.