There are several ways to do this, but since you mentioned 'scaling' in your thoughts I can point you in one direction.
Are you aware of the SCREEN WIDTH() and SCREEN HEIGHT() functions? In combination they return the current screen resolution, so that the code can determine what res it's running in. You can apply a multiplier to all your screen coordinates by calculating the multiplier as a ratio of some arbitrary source resolution (such as the resolution you were using when you built the code).
If you are building in 640*480, for example, and the program detects that it is running in 1280x960, your multiplier would be 2, and you'll multiply all screen coordinates by this value so that you keep objects in the same relative position on the screen.
You can calculate the multiplier dynamically by devising an appropriate formula that determines the ratio of the return values from SCREEN WIDTH() and SCREEN HEIGHT() to the resolution you are building in.
CONSTANT xmult# = SCREEN WIDTH() / buildresx
CONSTANT ymult# = SCREEN HEIGHT() / buildresy
Now multiply all screen coordinates and sprite scales that appear in your code by these multipliers.