Fixation point and image presentation

How do I have a fixation point never leave the screen while I present words
and shapes around it. I tried using the powerpoint-to-bitmap technique (print powerpoint screen) to
show the picture, but because the screenshot covers the entire screen, when I present the stimuli, it
covers up the fixation point that I have on the screen. So what I did was capture a fixation point and the object as an
entire picture...but there's a presentation delay and a slight movement of
the fixation point by doing this. If you have a solution to this, please
let me know.

So, now I have figured out a way to display only the stimuli and keep the fixation point in view.

Now my problem is how to keep the fixation point there after removing the stimuli from the screen. I have a fixation point on the screen, and then a diamond comes on the screen, and the subjects are required to make a response even though the diamond disappears after 100ms (rt:9,1,clear100) However, I don't want the fixation point to disappear with the diamond...I want the fixation to remain on the screen while the subject makes his/her response. How do I do this?
STIM LOC TIME STIM LOC TIME
~+<3> 0,0,1 150 D 0,.43,0 rt:9,1,clear100