Thanks, Shawn- that worked perfectly.
For anyone else trying to do the same thing, remember that the line and column numbers are not zero-based, meaning the first line in the file is line 1, not line 0, and the first column in a line is column 1, not 0. This can be a bit confusing when using the System.IO.File class's methods to get the index of the part of the file that's wrong, but it's easy to fix.
--
"Back in my day, we didn't have Wiis. The best we had were chunky, irregularly shaped systems that were named after their processors or whether they had color or not. You could only play them if you had three hands, the joysticks only lasted 2 weeks before falling out, and they used cartridges (those are like DS Cards, only way bigger, and they run on dust and spit), but most kids played ‘em anyway. The best games were about a little boy in a green skirt that killed an old puke-brown-skinned red-haired organ-playing dinosaur-man, kept a boomerang, a slingshot, a bow, and bombs in his pocketless tights, and befriended a cross-dressing princess that stalked him. There was also the one game about a short Italian plumber that ate wild mushrooms, jumped off walls, slaughtered cute little turtles just because they were in his way, and killed the last of the dinosaurs, a dragon named Bowser. Those were the days..."
--Michael Hoffmann