Crosshair?

Is it possible to make a crosshair hack? Because I need it.. I think it isn't that hard.. But I think you haven't got to make something that injects(or something like that). Just something that draws the crosshair on your screen and always stays in front.. What do you think??

Grab a pen, make a mark in the center of you monitor and... There you have it... After playing the game do not forget to erase it...

THere is a crosshair mod.. you should google it.. (its on another forum so..)