Thanks EmuZombie for this. Making login screens that work in any resolution is actually rather quite simple.
Simply by taking where you input the height and width and changing it to 0x0 you will cause the LogonUI program to automatically resize to fit the screen depending on the user's resolution settings.
The two kinds of tags that call bmp's look like this:
Now, knowing this information you may expand on this. Experimenting is the key here. As to whether or not this can be applied to moving objects around and still allow them to stay where you want them on the user's screen, I do not know. But I'm sure with the right about of playing around with the setting you should be able to do it.