Finding Pixel Location On Game

[Natedogg386]

Ok in the game i took a picture and opened it with paint but the location must be wrong or wront size or something I am running the game in 800 x 600 how would i find the right pixel position?

[scriptkitty]

normally I would display it at 100%, then move my mouse to the upper corner and record that x,y and move my mouse to the spot where I want, and subtract the x from the x, and the y from the y on the starting point. That would give a pretty good idea, but I ma sure there are more reliable ways.