Scratch

so i have an rpg my movement script is built so that the player is allways i the middle it is as follows

when flag clicked
set (x pos v) to[0]
set (y pos v) to [0]
forever if <(up arrow v) key pressed?>
change (y pos v) by [1]
wait [0.5] secs
end
forever if <(down arrow v) key pressed?>
change (y pos v) by [-1]
wait [0.5] secs
end
forever if <(right arrow v) key pressed?>
change (x pos v) by [1]
wait [0.5] secs
end
forever if <(left arrow v) key pressed?>
change (x pos v) by [-1]
wait [0.5] secs
end

now i would like a script that make object scroll on the screen

could someone tell me haw to do this use this as an example

the player can go all directions so i want a chest at (500, 500) witch is off the screen so i need a sprite that will allow the chest to move around the player making the illusion the player is moving around it.