Assuming you're using Cocoa, you can use the setFrame:display: method to set the frame, and then the frame method to get the frame of the main window and calculate the position based on that.
Are you talking about a dialog box from NSRunAlertPanel() or something like it? Because in that case, I don't think you're able to position it. You could always try writing your own alert box routine that would allow you to position it.
Are you talking about a dialog box from NSRunAlertPanel() or something like it? Because in that case, I don't think you're able to position it. You could always try writing your own alert box routine that would allow you to position it.