Ack...
It would seem I've given some bad advice with OverRun (my appologies to everyone). OverRun claims to be customizable, and I'd been putting it off, but took for granted that the functionality worked. I just tried customizing it, and it doesn't work. Further, in the process of troubleshooting, I noticed that it always appears at the top left of the screen.. very annoying after a while.
I've found a much better alternative called RunPlus. It's not customizable either, but it appears at the bottom left and looks exactly like the real run dialog (except that it doesn't start with the last command that was run in the field and highlighted). Plus, it adds some cool functionality to the context menu.
At any rate, it's available at the
PC Magazine website. I know, I know, you have to register to download, but hey, it's free.