80paddyb: Thanks. I tried KeyTweak already but I it just maps ` to another key. I couldn't find a way to get ~ without pressing the shift key (which doesnt work in the game). I could buy a USB keyboard but all of them also have the ~ key as a second function to the ` key. I wonder if I might run into the same problem?
Well, it's not important what you have to press to type "~" (in Word, for example). If I want to type "~" in Word I have to switch from Czech to English keyboard layout, press Shift and "~" first and then one more key for the "~" glyph to be displayed. And both my Asus notebook keyboard and my Logitech USB keyboard display four various glyphs (~, `, °;) on the "~" key. But in the game, I just have to press the "~" key (without Shift or switching to another keyboard layout) and the console works - a small ">" displays below my character's portrait in the top left corner. Also, the Shift + "~" combination works for me in the game as well.
To sum it up, while I can't guarantee that a USB keyboard will solve your troubles I don't think that it matters if it has the "~" key as a second function. Of course, the least expensive solution would be to borrow a USB keyboard from a friend/work/school/neighbour - just in case.