Yes, that is possible.
Put this code in your behavoir.
on mouseWithin
sprite(b).member=member("a"

sprite(b).locV=Vb
sprite(b).locH=Hb
end
Where b is the sprite channel number, a is the name of the graphic cast member, Vb is y coordinate for the reg. point of the graphic and Hb is the x coordinate for the reg point of the graphic on the stage (when the graphic appears on the stage.)
1. Now there is two ways to do this. First, you can make sprite b a graphic image and then move it off the stage, so the end-user will not see. Then the next two lines with locV and locH bring it out onto the stage.
2.Or you could go into the Paint editor of Director, do not create anything, just write blank in the field where you name it. It essentially becomes a cast member of nothing. So put it in the score on sprite channel b.
You do not even need the lines with locH and locV for this way; just position the blank cast member in the exact spot where you want the graphic to appear. The first line will simply switch the cast member of nothing with your graphic.
Then you probably want a handler for mouseLeave, so when you leave the country the graphic goes away.
For the first option
on mouseLeave
sprite(b).member=member("a"

sprite(b).locV=Vc
sprite(b).locH=Hc
end
The only thing different are the values for locV and locH. Hc and Vc are both the coordinates for the graphic to be offstage.
For the second option
on mouseLeave
sprite(b).member=member("blank"

end
The second option may be less work for you and easier to manage but i figured you might want more options.
Hope this helps.